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高村 則夫, 古賀 憲司, 山田 俊一, 溝口 富茂
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For a total synthesis of the optically active carene derivatives from optically active α-amino acids, several attempts were made on intramolecular cyclization of 2-cyclohexenyl esters of α-substituted-α-diazo acetic acid (3) which were derived from diazotization of the corresponding amino acid esters. Results of model reactions are shown in Table II. One of the optically active diastereoisomers (12) which was obtained by resolution of 2-cyclohexenyl-L-alaninate was diazotized by treatment with isoamylnitrite and then cyclized using Cu powder as a catalyst to afford the optically active lactone (15). (15) was then converted into the key intermediate (17) having the bicyclo[4.1.0] heptane ring system, from which (+)-car-2-ene was synthesized via the sequence, (17)→(18)→(19)→(20)→(21)→(22)→(23)→(+)-car-2-ene.
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藤本 康雄, 与倉 進, 中村 忠治, 森川 民雄, 辰野 高司
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Total synthesis of (±)-12,13-epoxytrichothec-9-ene (V), isolated from the metabolite of Trichothecium roseum by Nozoe et al, was accomplished.The keto-ester (VI) was reacted with crotonaldehyde to give a keto-aldehyde which was converted into the acetal (VII). The Meerwein-Ponndorf reduction of VII gave the cis-fused pyrane derivative (VIII). Reduction of VIII with LiAlH_4 afforded an alcohol (IX) which without purification was submitted to the next reaction because the alcohol (IX) was easily transformed to the compound (X) by silica gel chromatography. Tosylation of IX with p-TsCl-pyridine, followed by treatment of the resulting tosylate with LiAlH_4 gave the methyl derivative (XII). Selective attack of XII by m-chloroperbenzoic acid produced a diastereomeric mixture of the hydroxy ester (XIII) which was pyrolysed to the ketone (XIV). Allylation of XIV with allyl bromide did not give the C-alkylated product, but gave an unexpected O-alkylated compound (XVI). Rearrangement of XVI was accomplished by heating to give a mixture of XVII and XVIII in a 1:2 ratio. Treatment of XVIII with OsO_4-KClO_3 afforded the diol(XIX) which was cleaved by NaIO_4 to yield the keto-aldehyde monohydrate (XX). XX was cyclized with NaOMe to give a diastereomeric mixture of the tricyclic ketol (XXI) which was converted into the keto-iodide(XXV) by the action of (PhO)_3PMeI. Reduction of XXV with Raney-Ni gave the ketone (XXVII), while treatment of XXV with Zn-EtOH gave an undesired ketol (XXVI). Reaction of XXVII with dimethyloxosulfonium methylide produced an epimer (XXVIII) of 12,13-epoxytrichothec-9-ene. The Wittig reaction of XXVII with methylene triphenylphosphorane gave the corresponding methylene compound (XXIII) which was treated with m-chloroperbenzoic acid to afford (±)-12,13-epoxytrichothec-9-ene(V) after purification by preparative thin layer chromatography. The IR and NMR spectra of the final product was superimposable on that of the authentic sample kindly provided by Dr. S. Nozoe.
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鈴木 正昭, 長瀬 博, 加藤 真行, 加藤 金芳, 立松 洋, 毛利 哲也, 山田 静之, 平田 義正
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Efforts have been made to establish a method of synthesizing the picrotoxane sesquiterpenoids such as picrotoxinin (1) and tutin. Starting from the acid (6), the intermediate (11) possessing the isotwistane skeleton was prepared in a stereo-controlled manner. The tricyclic compound (11) was transformed into the bicyclic compound (27) by the following sequence: (11)→(12)→(13)→(14)→(15)→(16)→(18)→(26)→(27). The bicyclic intermediate (27) was further converted to the compound (30).
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野老山 喬, 松尾 圭造, 金沢 礼三, 小槻 日吉三, 久保田 尚志
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Portulal 1 is a perhydroazulenoid diterpene which has clerodane substitution and was originally isolated as a plant growth regulator from Portula grandiflora. The studies aimed at the total synthesis of this interesting compound will be presented in this lecture. The Diels-Alder reaction of chloromethyl maleic anhydride with 1-vinylcyclohexene proceeds stereospecifically to afford an adduct 13 which has the desired configuration in the three of four asymmetric centers present in 1. Prior to the construction of the remaining center at the angular position, 13 was transformed to an intermediate 25 with perhydroazulenoid skeleton in highly efficient manner including 8 steps. The introduction of the angular substituent was performed by the intramolecular alkylation and the following cleavage of the newly formed ring. The product 30 was converted via 32 to the dilactone 33, which was found to be identical with the one, derived from natural portulal via 37 in 9 steps. Thus our synthetic intermediate is confirmed to possess the correct stereochemistry in all diastereomeric centers. The synthetic path to give back 1 from 37 has been also elaborated. Therefore, provided that the missing link between 32 and 37 is connected, a formal total synthesis of portulal will be completed. The work in this line is in progress.
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賀佐 伸省, 松永 政司, 浜中 信行, 松本 毅
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Through the sequence of reactions outlined below, the dl form of tricyclic diketone B has been synthesized. Since the optically active form of B has been obtained from grayanotoxin II and has been reverted to the starting natural product, the present synthesis means formal total synthesis of grayanotoxin II.
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冨士 薫, 中野 重利, 藤田 栄一
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The syntheses of compound 1, grayanol A and B have been attempted, and the following experiments were carried out. The compound 3 was converted into the cleaved product 19 containing a ten-membered ring system through the route shown in Chart I. The compound 19 was cyclized into compound 21. The compound 4, the C-9 epimer of 5, was transformed into cyclodecanone 32 through the passway via 22 to 31, but an attempted isomerization of the double bond was not successful. The CD ring system of grayanols was synthesized through the sequence shown in Chart III. The cyclodecanone system which corresponded to that of 1-deoxygrayanol was synthesized starting from compound 34 by the route shown in Chart IV. The investigations for the final synthetic steps are in progress.
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田原 昭, 秋田 弘幸, 水野 博光, 滝沢 登志雄, 大塚 晏央, 馬越 貴子, 中田 忠
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Benzonilidene compounds (2 and 30) derived from abietic acid (1), can be regarded as a kind of dienone and aroused our interest in its reactivity. It have been found that the benzonilidenes behave in completely different manner (I〜III type rearrangement) according to the variation of the reagent and their structures. 1). I-Type Rearrangement. (2)(c.H_2SO_4-Ac_2O, 63% Y.) ⇄ (3)(c.H_2SO_4, quant. Y.). The electrophilic reagent could be attacked successfully to C_1-position to give (4) and (5) through the rearrangement. 1-a application). Synthesis of Teideadiol (5→6). 1-b application). Transformation to Grayanotoxin Skeleton (5→11). 2). II-Type Rearrangement. (2)(AlCl_3)→(15)(51% Y.)+(16)(5% Y.)+(2)(15% Y.). 3). III-Type Rearrangement. (30)(c.H_2SO_4-Ac_2O)→(31)(82% Y.).
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白崎 英一, 青柳 玲子, 廣田 洋, 舘江 栃郎, 山田 修三, 露木 孝彦, 高橋 武美, R. Stevenson
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Photochemical reaction of friedelin (1), shionone (2), norfriedelin (3), lupan-3-one (4), and 1,5,5,9-tetramethyl-2-trans-decalone (36) was investigated. The products formed from friedelin (1) in various solvents are summarized in Table 1. Since 1 bears no hydrogen atom on the δ-carbon atom, an acylalkyl biradical produced from 1 can not give a δ,ε-unsaturated aldehyde via a 6-membered transition state, but give the ketene (16) by hydrogen transfer from C-2 to the alkyl radical. In protic solvents, 16 gave addition products such as the seco-acid (12) and the seco-ester (10). In aprotic solvents, 16 survived and suffered autoxidation in the subsequent separation procedures to give the seconor-aldehyde (7) and the seconor-acid (13). The acylalkyl biradical also gave 1 and 4-epifriedelin (9) by recyclization, norfriedelane (5)(along with its 4-epimer) and the unsaturated nor-hydrocarbon (6) by decarbonylation, and an ε,ζ-unsaturated aldehyde (8)via an 8-membered transition state. 4-Epishionone (23) was obtained on irradiation of 2. Photochemical interconversion between norfriedelin (3) and the unsaturated aldehyde (24) was observed. Irradiation of the decalone (36), a bicyclic model compound related to 1, and the subsequent separation work-up gave the secoaldehyde (37), the seconor-acid (38), and the seco-acid (39). Photoreaction of lupan-3-one (4) in n-hexane gave three seco derivatives (27, 29, and 30), besides the seconor-acid (28) formed during the subsequent work-up. A lactone (31) was also obtained. Putranjivic acid (17) was synthesized in one step from 1.
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笠井 良次, 新造 慶子, 田中 治
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The synthesis of dammaranediol-II(VI) from hydroxyhopanone(III) has already been reported. In an attempt toward the synthesis of 20(S)-protopanaxadiol(I) from VI, the introduction of a hydroxy function to C-12 of the dammarane skeleton has been studied. A solution of p-nitrobenzoate(XI) of 3-epi-dammaranediol-I(X) in tert.BuOH was irradiated for 40 hr and the products were saponified to give octakisnordammarane-3α,17β-diol(XII). From the crude irradiation products, 2-methyl-6-heptanone(XIII) was isolated and identified. Whereas, the irradiation of p-nitrophenylacetate(XIV) of 3-epi-dammarandeiol-II(IX) under the similar condition followed by saponification yielded the 12α-hydroxy compound(XV). p-Nitro-phenylacetate of X also afforded the 12α-hydroxy compound by the similar sequence of the reaction. In case of β-(p-nitrophenyl)propionate of IX, the similar hydroxylation reaction was observed but production of the compounds other than XV was increased. The 12α-hydroxy compound(XV) thus obtained was converted to betulafolienetriol(XVI) and 20(S)-protopanaxadiol(I) furnishing the synthesis of the Ginseng sapogenin.
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松尾 昭彦, 佐藤 彰一, 中山 充, 林 修一
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In connection with our previous investigations on sesquiterpenoids of the liverworts, a new sesquiterpene ketone was isolated from Mylia taylorii (Hock.) Gray together with (-)-myliol(I). The compound was named (-)-taylorione, and the structure and absolute configuration were determined as formula II on the basis of chemical and spectral evidences. (-)-Taylorione(II) are constituted of a novel carbon skeleton containing a cyclopropane and a cyclopentene rings, and it may be biosynthesized from an enantiomeric aromadendrene-type precursor, which is also common to the biosynthesis of co-occurring (-)-myliol(I), via the oxidative cleavage of the C_1-C_<10> bond.
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河津 一儀, 三井 哲夫
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A piscicidal substance named vibsanine A (1), C_<25>H_<38>O_4, [a]_D+19.6°(CCl_4), TLm against Oryzias latipes 0.1 μg/ml and a plant growth inhibitor named vibsanine B (11), C_<25>H_<36>O_5, mp. 83.5-85℃, [α]_D, +85°(CCl_4), IC_<50> against root growth of rice seedlings 60 μg/ml have been isolated from the leaves of Viburnum awabuki (Caprifoliaceae), a fish poison used in Okinawa Prefecture. Both compounds are β,β-dimethylacrylic acid esters of diterpene alcohols. On the basis of the spectral studies of both compounds and their derivatives and oxidation products, the chemical constitutions of (1) and (11) have been elucidated. It is the first case that diterpenoids with humulene skeleton are encountered.
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佐々 武史, 高浜 昭博
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Cotylenol, the aglycone of cotylenins, and cotylenins A, B, C, D and E were isolated from the culture filtrate of a fungus, which is believed to be a Cladosporium sp.. Their structures were elucidated on the basis of spectral data and chemical evidence. Cotylenol(1) is a rare diterpene with the ophiobolane skeleton. Cotylenin E(2) is a cotylenol glucoside, which has a primary structure in a series of cotylenins. Cotylenins C(3) and A(4) are unusual fungal glycosides having a novel sugar moiety and the only related compound, fusicoccin A, is a phytotoxic metabolite of the plant pathogen Fusicoccum amygdali Del. Cotylenins B and D are derivatives of cotylenin A and these minor products could be indirectly derived from cotylenin A.
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北川 勲, 菅原 民雄, 吉岡 一郎
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It has been known that various species of sea cucumber and starfish(Phylum Echinodermata) contain saponin as the toxic principle. In 1968, Elyakov,et al. reported the isolation of two triterpenoid glycosides (stichoposide A and C) from the MeOH extract of Far Eastern sea cucumber (Stichopus japonicus) and proposed the structure of two aglycones, stichopogenin A_2(1) and A_4(2), which were obtained by acid hydrolysis of stichoposide A. On the other hand, in 1969 Shimada isolated an antifungal glycoside named holotoxin from the same species of sea cucumber. However, the structures of these glycosides have not been elucidated. In the present study, we have isolated holotoxin (identical with the Shimada's specimen), which has been separated into three glycosides now designated as holotoxin A (major), B, and C by droplet countercurrent chromatography. Upon ordinary acid hydrolysis, holotoxin A furnished xylose, quinovose, 3-O-methyl-glucose, glucose, and a mixture of aglycones, Ge-1 (a mixture of 1 and other double bond isomer) and 2, while under the mild acid conditions, 2 and 6 were isolated. Based on the chemical and enzymatic degradation of holotoxin A and its derivatives in conjunction with the physicochemical analyses thereof, the structure of holotoxin A has been established as 8, which is characteristic by the possession of two α-linkages of xylose and quinovose. Finally, the antifungal activity of holotoxin A, B, and C has been summarized as shown in Table 2.
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河合 賢一, 荻原 幸夫, 秋山 敏行, 飯高 洋一, 柴田 承二
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Some saponins of Rhamnaceae and Scrophulariaceae plants produce ebelin lactone (7) on acid hydrolysis. As ebelin lactone seems to be an artifact the isolation of the genuine sapogenin of such saponins has been studied. On Smith-de Mayo degradation of jujuboside B, a saponin of the seeds of Zizyphns jujuba and hovenoside G, a saponin of the root-bark of Hovenia dulcis a genu ine sapogenin, jujubogenin, was yielded. The chemical and spectroscopical investigations showed that jujubogenin is represented to be 3β,20-dihydroxy-16β(23), 16β (30)-dioxidodammara-24-ene, and the X-ray analysis of its p-bromo-benzoate revealed the absolute configuration at 20 and 23 as being S and R, respectively. The mechanism of conversion of jujubogenin into ebelin lactone has been elucidated. Bacoside A, a saponin of Bacopa monniera which also produces ebelin lactone along with bacogenin A, on acid hydrolysis has been found to yield jujubogenin and another sapogenin tentatively named sapogenin-O by the Smith-de Mayo reaction. The structure of genuine sapogenin of bacoside A is now beeing studied.
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林 紘司, 三橋 博
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a) Partial acetylation of sarcostin (1) gave two diacetate; 3,12 diacetate (3) and 3,20 diacetate (4) with the ratio of 3:1, besides 3-mono acetate (2) and 3,12,20-triacetate (5). On the other hand, benzoylation of 2 with equimolar amount of BzCl gave 20-benzoate (6). b) Treatment of 1 with paraldehyde under acid catalyzed conditions afforded 14,17 and 12,20 bis-O-cyclic ethylidene derivative (14). c) The configuration of C-20 carbinol of 1 is S-configuration on the basis of X-ray analysis of 3-p-bromobenzoate (17). C-20-o-Nitrobenzoate (18) showed a negative Cotton effect contrary to the expection from Nagai's data but the 14,17-O-ethylidene derivative (19) showed a positive Cotton effect. d) It has been known that reduction of pregnan-20-one with metal hydride gives β-alcohol (R-configuration). It is deduced, however, that the stereochemistry of the C-20-carbinol from the orresponding ketone by NaBH_4 reduction dues to the configuration at C-17 position regardless of C/D ring juncture from the conformational analyses of pregnan-20-one derivatives by the ORD octant rule (Fig. A and B). The C-20-O-o-nitrobenzoate (25) from the reduction of lineolondiacetate (24) with NaBH_4 shows a positive Cotton effect while the o-nitrobenzoate (27) from isolineolondiacetate (26) shows a negative. These results agree with the deduction.
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安田 新, 田中 慎, 大嶌 幸一郎, 山本 尚, 野崎 一
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The reaction of epoxides with strong base constitutes well-known synthetic methods for the preparation of allylic alcohols. Because of our needs to carry out such transformation under very mild condition, we developed a new method based upon diethylaluminum dialkylamide. The method takes advantages of the affinity of aluminum metal for oxygen. Diethylaluminum tetramethylpiperidide (DATMP) has proved to be most satisfactory for the above isomerization, and several epoxides are converted to the corresponding allylic alcohols in high yields with high regio- and stereospecificities at 0°for 2-3 hr. Thus, the Z-epoxide 3 gives the disubstituted allylic alcohol 4, while the E isomer transforms to the alcohol 6. General synthetic method for the conversion of allylic alcohols to diene compounds with high specificity is enunciated. The method depends heavily on the application of DATMP promoted oxirane rearrangement described above. Myrcene, trans-ocimene, β-, and α-farnesene are synthesized from their biological precursor, nerol, geraniol, cis-, and trans-farnesol, respectively.
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磯江 幸彦, 早瀬 善男, 金 東海, 岡本 真人, 舟槻 源右衛門, 目 武雄
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I. Synthetic studies of drimane and labdane-type terpenoids via photo-electrocyclic reaction of trienes involving enolate double bond. Irradiation of β-keto-ester 1 with high pressure mercury lamp in methanol in the presence of 2-molar excess of sodium methoxide gave bicyclic enolate ester by electrocyclic reaction involving triene in a conrotatory manner and subsequent protonation gave highly stereoselectively a key decalone derivative 4. 1). Five stage synthesis of hydroxy lactone 19 accessible to bemarivolide starting from key decalone derivative 4 is described. 2). Six stage synthesis of γ-hydroxy enone 28 accessible to 6-oxogrindelic acid starting from key decalone derivative 4 is described. II. New synthesis of cyclopentenols via intramolecular photo-oxentane formation. Several cyclopentenol derivatives accessible to natural products were synthesized in moderate yield by the irradiation of olefinic β-keto ester derivatives followed by treatment with sodium hydride. III. Photosensitized oxygenation of highly skewed polyenes. Photosensitized oxygenation of cis-β-ionol prepared from trans-β-ionol by photosensitized isomerization of double bond afforded in high yield a mixture of allenic diol and exomethylene diol in the ratio of 1:2.
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森 謙治, 富永 道明, 滝川 哲夫, 松井 正直
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A stereo-controlled synthesis of the pheromone of pink bollworm moth, (Pectinophora gossypiella Saunders), that is, 7-cis, 11-cis-hexadeca-dienyl acetate (5) and its 11-trans-isomer(6), was achieved using the Grignard coupling reaction. (1R:7R)-(+)-exo-Brevicomin (17) and its antipode (17') were synthesized from (2S:3S)-D(-)-tartaric acid and its antipode, respectively. This established the absolute configuration of the both enantiomers of exo-brevicomin, the pheromone of western pine beetle (Dendroctonus brevicomis Le Conte). Bioassay of our material was kindly carried out by Professor D.L. Wood and Mr. L.E. Browne of University of California, Berkeley, and showed that only the (+)-isomer (17) was biologically active. This firmly established the chiral nature of the pheromone receptor of the insect.
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酒井 浄, 小田 修
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It is well known that the Prostaglandins have a various pharmacological activity, ex. an uterin muscle stimulant activity, an inhibition of gastric acid secretion, a bronchodilation activity. As a part of program to elarify the relationship between pharmacological activity and the structure, we undertook the total synthesis of 11α-hydroxymethyl Prostaglandins, in hope that those compounds will exhibit higher and or more selective biological activities than naturally occuring Prostaglandins. The trans-cis lactone (4a,4b) derived from readily prepared dimethoxy carbonyl cyclopentanone (1) has a structural advantage that C-2α will be stereospecifically alkylated by a various alkylating agent leading to PGE_1,PGE_2, 5-dehydro PGE_2 form, and the alkylated lactone (6a,6b) will be deearboxylated without any change of configuration to afford the common key intermediate (7a,7b) to PGE_1 or 11α-hydroxymethyl PGE_5. An optical resolution of (14) using d-ephedrine gave an optically active half ester (15), in which an absolute configuration was determined by two method. A) degradation of Brefeldin A. B) derivative from the enantiomer of Corey's synthetic intermediate. In addition to PGE_1 from (7a), (-)11-deoxy-11α-hydroxymethyl PGE_1, (±)11-deoxy-11α-hydroxymethyl PGE_2, (±)11-deoxy-11α-hydroxymethy1-5-dehydro PGE_2 were stereospecifically synthesized. (-)11-deoxy-11α-hydroxymethyl PGE_1 showed the same power as PGF_<2>α for uterine contraction in pregnant rat, and a diarrhoea as a side effect of natural PGE was not observed.
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正宗 直, 松江 一, 村瀬 久, 小野 光則
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In a study aimed at the total synthesis of laurencin (1) and related compounds (2), we prepared 7,8-dihydro-2-ethyl-8-formyl-2H-oxocin-3(4H)-one ethylene acetal (3) and its derivative (46). 4-Ethyl-2-hydroxymethyl-3-oxaglutaraldehydes (20), prepared by ozonization of 5-ethyl-2-hydroxymethyl-2,5-dihydrofurans (9) (Chart 1), were submitted to the Robinson-Schopf condensation with methylamine and acetonedicarboxylic acid to give 9-methyl-9-aza-3-oxabicyclo[3.3.1]nonanes (21〜23) (Chart 3). These compounds were degraded via a several-step process into oxocin derivatives (38a〜38c) (Chart 5). One of these compounds (38a) was then converted into (3) and (46), important synthetic intermediate for laurencin (1).
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伴 義雄, 大沼 毅, 関 興一, 大石 武
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セッションID: 21
発行日: 1974/10/01
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The total synthesis of the entitled poly-cyclic indole alkaloids has been achieved from a common intermediate. (1) Total synthesis of (±)-deoxyaspidodispermine(1) Compound(6) was prepared from 2-hdyroxytryptamine and its stereochemistry fully elucidated. It was treated with oxygen at -78°for 2 hr in a solution of NaH in Bu^tOH and dimethylformamide containing triethyl phosphite to give the hydroxy-derivatives [7a(51%) and 7b(5%)]. The ketol(7a) was reduced with LiAlH_4 in DME by refluxing for 1 hr to furnish 8 (31%) with 9a and 9b. The compound(8) was acetylated and hydrogenated with Adams' catalyst to give (±)-deoxyaspidodispermine(1), which was identified with the authentic sample of the natural alkaloid. (2) Total synthesis of (+)-1-acetylaspidoalbidine(10) Compound(6) was submitted to the Michael condensation with ketene thioacetal monoxide in DME containing lithium diisopropylamide at room temperature for 2 hr to afford 15a (38%) and 15b (37%), a mixture of which was hydrolyzed by refluxing for 0.5-1.5 hr in aqueous acetonitrile containing perchloric acid to give the corresponding aldehyde(17) in a quantitative yield. The aldehyde (17) was reduced with LiAlH_4 to give the alcohol (18), which was acetylated and hydrogenated with Adams' catalyst, affording 21 as an amorphous solid. On oxidation with mercuric acetate, 21 gave (±)-1-acetylaspidoalbidine(10), which was identical with the authentic specimen of the natural alkaloid.
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高野 誠一, 畑山 範, 平間 道康, 斎藤 鶴子, 穴戸 宏造, 菅原 勉, 小笠原 国郎
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A GENERAL SYNTHETIC METHOD OF THE NON-TRYPTAMINE PART OF THE INDOLE ALKALOIDS via SULFUR CONTAINING INTERMEDIATES HAVE BEEN EXAMINED. WE WILL REPORT TWO METHODS; THE α-DIKETOMONOTHIO-KETAL CLEAVAGE AND THE THIO-CLAISEN REARRANGEMENT, WHICH ARE EXPECTED TO BE USEFUL FOR THE SYNTHESIS OF THE ASPIDOSPERMA TYPE AND IBOGA TYPE INDOLE ALKALOIDS.
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坂井 進一郎, 新間 信夫
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Pleiocarpamine 3, an interesting indole alkaloid of apocynaceae plants, has C-mavacurine skeleton. We wish to report that a partial synthesis of 20α-ethyl-19,20-dihydro-16-epi-pleiocarpamine 16 have been accomplished starting either from hirsutine 4 or dihydrocorynantheine 5. Treatment of desmethylhirsutine 7 (or desmethyldihydrocorynantheine 8) with BrCN/ 0.6% EtOH-CHCl_3 (or 20% EtOH-CHCl_3 for 8) then gave a mixture of 3-(R)-ethoxy- and 3-(S)-ethoxyderivatives 9a,b (sole C_3-(R), 9a from 8). The epimeric mixture 9a,b (or 9a itself) was oxidized to yield C_<16>-deformyl-chlorinated compound 11 with t-BuOCl at -78°. The new ring formation between Na and C_<16> of 11 was accomplished to give the C_3 epimeric mixture 14a,b (or a pure C_3-(R), 14a mp157-158°, from C_3-(R)- 11a) by treatment with NaH in DMSO. The final ring closing reaction of 14 (either from the C_3 epimeric mixture 14a,b or C_3-(R) 14a itself) was achieved by heating with aq.HOAc/ NH_4OAc to give 16, 20-α-ethyl-19,20-dihydroepi-pleiocarpamine mp 169-171°, (C_<20>H_<24>O_2N_2) and an indoline derivative 17. The compound 16 was reduced to the corresponding alcohol 18 (20-α-ethyl-19,20-dihydronormavacurine) with LiAlH_4. The mass spectrum of this alcohol 18 showed the same fragmentation peaks and the similar relative intensities as recorded for 20-β-ethyl-19,20-dihydronormavacurine derived from the natural alkaloid.
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原山 尚, 大谷 光昭, 沖 正信, 犬伏 康夫
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Serratinine (1), an alkaloid from Lycopodium species, has been synthesized. The Diels-Alder reaction of (9) derived from (11), with butadiene gave the compound (10), which was successively treated with Zn-AcOH, NaBH_4, AC_2O-Py., and OSO_4-NaClO_3 to afford the alcohols (18), (19), and (20). Hydrogenation of the acetonide of (18), followed by acid hydrolysis gave the compound (22). The compound (22) was also obtained from (19). Oxidation of (22) with HIO_4 provided the dialdehyde (24). Treatment of (24) with basic alumina or with a trace of piperidine acetate in dry benzene gave only the compound (25), whereas treatment of (24) with excess pyrrolidine acetate in dry MeOH afforded selectively the compound (26). The Wittig reaction of (26) gave the compound (35) which was hydrogenated over (φ_3P)_3RhCl to afford (36). Reduction of (36) with CoCl_2-NaBH_4 yielded the compound (37) which was treated with NCS and Cu_2Cl_2 to give the aziridines (38) and (39) in 20 and 3%, respectively. Reduction of (38) with LiBH_4 provided the alcohol (40), which on treatment with TsCl-Pyridine gave the quaternary base (41). When refluxed with AcOK in EtOH, the compound (41) gave the triacetate (42), and hydrolysis of (42), followed by oxidation with Jones'reagent afforded the triketone (45). Finally, reduction of (45) with NaBH_4 gave dl-serratinine (46) and dl-8-episerratinine (47).
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礒部 公明, 多賀 淳一, 津田 喜典
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Stereoselective total syntheses of Amaryllidaceae alkaloids, crinamine, 6-hydroxycrinamine, criwelline, and macronine which have C_3-α-methoxy group were achieved as follows, starting from the Diels-Alder adduct (12) of 3-(3',4'-methylenedioxyphenyl)-Δ^2-pyrrolin-4,5-dione and butadiene. Borohydride reduction and acetylation of (12) yielded (30). Treatment of (30) with PhSeSePh and N-bromoacetamide in methanol followed by peroxide oxidation and elimination afforded a desired allyl-methyl-ether (40) in about 35% yield. The imino-ether (43) prepared from (40) by Meerwein reagent were smoothly reduced by NaBH_4-SnCl_4・2Et_2O complex in glyme into (20), the common intermediate to the title alkaloids. (±)-Crinamine (6) was obtained by heating the hydrochloride of (42) with formaldehyde. Formylation of (20) and heating of the resulted formate with POCl_3 yielded (45) which on hydrolysis gave (±)-6-hydroxycrinamine (7). Methylation of (45) followed by alkaline treatment afforded (±)-criwelline (9). (±)-Macronine (10) was synthesized via a lactam intermediate (48).
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花岡 美代次, 小川 信男, 佐々 博紀, 堀 伸子, 示沢 千恵子, 清水 憲治, 荒田 義雄
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Lythraceae alkaloids possess the unique structures having a trans- or cis-quinolizidine ring with a biphenyl or biphenyl ether and a twelve- or fourteen-membered lactone. The Mannich reaction of isopelletierine (1) with arylaldehydes under alkaline condition afforded cis-4-arylquinolizidin-2-ones, which then isomerized into the corresponding trans-quinolizidines. The stereoselectivity of this reaction was found to depend on solvents, solubilities of the starting aldehydes and the products, and reaction time. Based on the above observation, the first total synthesis of one of these alkaloids, decaline (17) having a trans-quinolizidine ring, was accomplished starting from 6-bromoisovanillin (8). (±)-Vertaline (26) having a cis-quinolizidine ring, (±)-desmethyl-decaline (34), and (±)-methyldecinine (45) having a biphenyl linkage, were also synthesized. The proposed structure (58) for lagerine required revision because the synthetic racemic compound (58) was found not to be identical with lagerine. The total synthesis of (±)-methyllagerine established its revised structure (69).
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赤須 通範, 糸川 秀治, 藤田 路一
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Five new fluorescent compounds, cepharanone A, B, cepharadione A, B and norcepharadione B were isolated from the neutral fraction of the callus tissue of Stephania cepharantha. Cepharanone A and B were aristololactam derivatives, and the structure of them were decided as (I) and (II). Cepharadione A, B and norcepharadione B had ketolactam in the B ring of aporphine skeleton, and the structure of them were proposed as (III), (IV) and (V) on the basis of their spectral data. The isolation of these compounds, related to aristolcilactam, from the natural sources was very interesting problem from the chemotaxonomical and biogenetical point of view.
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小菅 卓夫, 横田 正実
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As a cardiac principle of aconite root, Yokonoside had been reported by us in previous meeting, but synthesized Yokonoside did not have any biological activities. Then, separating procedure had been reinvestigated to obtain the true cardiac principle. In order to remove the inactive glycoside, the fractn. III was subjected to counter current distribution of n-buthanol-0.1N-HCl solvent system. And a crystalline matter (mp.260°), was obtained as colorless plate from the active fractn. IV as HCl-salt. The principle stimulates flog's heart even in ten billionth dilution, thus it was designated as Higenamine. Higenamine was identified as dl-demethyl coclaurine [V] from the spectral data and in comparison with synthesized authentic sample.
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百瀬 雄章, 尾崎 裕
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A rule concerning the determination of the conformation and configuration of the allylic (benzylic) hydroxyl group in 1-tetralols or 4-chromanols by NMR measurement was elaborated. The rule consists of the comparison of the acetylation mobility (Δ Ac), the differrence in chemical shifts of allylic protons between the alcohols and the corresponding acetates, for a pair of isomers, while the conventional method comprises the determination of the vicinal coupling between the allylic proton in question and the proton on the adjacent carbon atom. It was found that the value (Δ Ac_<eq>) for quasi-equatorial proton of one isomer was always larger than that (Δ Ac_<ax>) for quasi-axial proton of the counterpart. This regularity should be attributed to the preferred orientation of the O-H bond for axial and equatorial conformation and to the resulting anisotropic deshielding effect of electron lone pairs of the hydroxyl oxygen. This "Acetate Rule" could successfully be applied to the stereochemical assignment of several 1-tetralol and 4-chromanol derivatives and natural products. For example, the value (Δ Ac in CDCl_3) larger than 1,24 corresponds to the quasi-axial allylic hydroxyl, and that smaller than 1,17 to the quasi-equatorial one in simple flavanols.
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井上 博之, 上田 伸一, 井上 謙一郎, 林 利光, 塩原 義則
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o-Succinylbenzoic acid (OSB), 2-carbomethoxy-4-hydroxy-α-tetralone, catalponone and the related substance variously labeled with ^<14>C and ^3H were administered to Catalpa ovata. Detailed examination of catalpalactone, catalponol and α-lapachones isolated from the plant revealed the following biosynthetic pathway: 2-Carboxy-4-hydroxy-α-tetralone formed by the reductive cyclization of OSB is subjected to prenylation and decarboxylation to give 2-epicatalponol, which undergoes epimerization giving catalponol. On the other hand, oxidation of 2-epicatalponol gives 2R-catalponone, which is further converted into catalpalactone and α-lapachones. On the basis of this pathway, the biosynthesis of 1-naphthylisopentyl ether, 2,2-dimethylnaphthochroman, nordihydrolapachenole, tetrahydrotectol etc. was also discussed. This route is highly suggestive of the biosynthesis of phylloquinone, menaquinones as well as anthraquinones such as alizarin and morindone.
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菅 隆幸, 平田 敏文, 小山 文裕, 越谷 修, 村上 映子
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The structure of aloenin, a bitter glucoside from Aloe arborescens Mill. var. natalensis Berger which is used in domestic medicine, has been reinvestigated by a combination of the chemical and spectroscopic methods, and we now wish to revise the structure as 6-(2'-β-D-glucopyranosyloxy-4'-hydroxy-6'-methyl)phenyl-4-methoxy-2-pyrone (II). The biosynthetic pathway of this compound is of considerable interest because of its "masked polyketide structure." The ^<14>C-labeling pattern in aloenin (II) biosynthesized from [2-^<14>C]malonate, [1-^<14>C]acetate, [1-^<14>C]- and [3-^<14>C]phenylalanine, and [methyl-^<14>C]-methionine in Aloe plant demonstrated that the carbon skeleton of aloenin is generated by the acetate-malonate pathway and that the methyl of the methoxyl group is originated from methionine.
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西長 明, 東條 哲夫, 冨田 春生, 松浦 輝男
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Base catalyzed oxygenation of flavonols has been demonstrated to provide a model for the reaction of quercetinase, a dioxygenase from Aspergillus flavus. However, when hydroxy group is substituted at 7-(5-)position of the flavonols, the oxygenation is found to change the reaction path completely. The oxygenation of 4',7-dihydroxyflavonol in an aqueous alkaline solution gave p-hydroxyphenyl-glyoxylic acid and 2,4-dihydroxybenzoic acid and in an absolute methanol solution containing MeONa gave p-hydroxyphenylglyoxylic acid, methyl p-hydroxyphenylglyoxylate, and methyl 2,4-dihydroxybenzoate. The results are rationalized by assuming that intramolecular decomposition of hydroperoxide intermediate formed in the reaction course is depressed by conjugation of the hydroxy group at 7-position to carbonyl group at 4-position, and resulting triketone intermediate formed by intermolecular oxido-reduction undergoes further oxidative solvolysis. Co-salen catalyzed oxygenation of flavonols in DMF quantitatively gave the corresponding depsides even when hydroxy group is substituted at 7-position, where effect of the oxygen function on the catalysis is reflected only on the reaction rate, which is in order of 4'-OH>7-OH, OH>OMe>H. The present results indicate that in the oxygenation of flavonols the conditions where hydroxy group at 7-(5-)position is not dissociated is essentially needed to give the same product as that in the enzyme reaction.
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山崎 幹夫, 前林 行雄, 加藤 文男, 小山 泰正, 野老山 喬
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The ^<13>C-NMR spectra (Fig.3 a-e) of sclerin which was obtained by feeding formate-^<13>C, acetate-1-^<13>C and -2-^<13>C and malonate-2-^<13>C respectively to the culture of Sclerotinia sclerotiorum, indicated a good participation of those compounds to the biosynthesis of sclerin (I). The spectra also clarified the positions of incorporation of ^<13>C-atom of those labeled precursors in the molecule of I. The spectrum in Fig. 3-e particularly showed that I should not be derived from two polyketomethylene chains contrary to the hypothesis proposed previously, since ^<13>C from malonate was strongly labeled C_4 of the aromatic ring of I. The result indicated that I must be derived through one chain of polyketomethylene. From the result shown in Fig.5, the source of "extra methyl" of aureothin (IX) was confirmed to be the methyl of propionate, and two carbons at C_6 and C_7 of IX were demonstrated being derived from an acetate through "Route B" in Fig. 4. The propionamide moiety of aureothiicin (XI) has simultaneously been ascertained to be formed by the direct incorporation of propionate.
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鈴木 和夫, Masato Tanabe
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The origin and fate of protons play an important role in understanding the detailed mechanism of natural products biosynthsis. Here to fore a biosynthetic studies with carbon-13 have only been concerned with the origin of carbon skeletons. We report the use of ^<13>C-D coupling as a new method for the detection of the fate of protons during the biosynthesis of natural products. [S-^<13>CD_3]-(90% ^<13>C, 99.8% D_3)-L-Methionine was fed to the fermentation media of Pseudeurotium ovalis. Ovalicin (graphinone) and ergosterol were isolated from the broth and mycelia. In the case of ovalicin the O-methyl carbon appeared as a septet (1:3:6:7:6:3:1) with an isotope shift in the ^<13>Cnmr spectrum. On the other hand the C_<28>-methyl carbon of ergosterol appeared as a mixture of quintet (1:2:3:2:1) and triplet (1:1:1) signals. These results show that the mechanism of O-methylatian and C-methylation from the C_1 unit of methionine are different. The results of a ^<13>CH_3-^<13>CO_2Na (90% enriched) feeding experiment indicate that a bergamotene type intermediate is compatible in ovalicin biosynthesis.
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瀬戸 治男, Masato Tanabe
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The biosynthetic pathway of sterigmatocystine, a metabolite of Aspergillus versicolor, was studied by labeling the metabolite with ^<13>CH_3^<13>CO_2Na. The ^<13>C-nmr spectrum revealed that sterigmatocystine is formed from tetraketide through pathway (b) as shown in Fig. 1. The same technique was also applied to investigate the biosynthesis of penicillic acid. The result shown in Fig.3, pathway (a), was completely in agreement with the conclusion obtained by Mosbach.
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池川 信夫, 粟田 則男, 茅野 春雄, 桜井 勝, 大滝 哲也, 宮崎 浩, 石橋 正兀, 阿武木 秀夫
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There has been no direct evidence to establish that the prothoracic glands are responsible for ecdysone synthesis. Our improved culture system, in which the isolated prothoracic glands of the Bombyx silkworm were cultivated in hemolymph medium under a continuous supply of excess oxygen, led to first successful result. A typical set of data (Table 1) reveals that a considerable amount of hormonal activity is found in the medium. The hormonal fraction was extracted from the culture medium and applied to a TLC plate. The results revealed that all the hormonal activity was located in a distinct region corresponding to α or β-ecdysone. The ecdysone fraction was submitted to high pressure liquid chromatography. Only fraction 8 (Fig. 5) having the same retention time with α-ecdysone had the hormonal activity On the other hand, a specific gas phase analysis of zooecdysones using mass fragmentography of trimethylsilyl derivative was developed. Quantitative estimation of 10^<-10> g level of α and β-ecdysone can be obtained by focusing at m/e 564 and 561, respectively. Analysis of the fraction 8 by this technique clarified that the hormone obtained from organ culture is α-ecdysone.
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芝 哲夫, 椋木 康雄, 秋山 仁
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Longicatenamycin is a new peptide antibiotic which was isolated from Streptomyces diastaticus S-520 and reported to be effective against Gram positive bacteria. This is a mixture of congeners of cyclic hexapeptide with three exchangeable amino acid residues. Constituent amino acids were established to be each one mole of glycine, D-ornithine (D-lysine), D-valine (D-isoleucine), threo-β-hydroxy-L-glutamic acid, L-α-amino isooctanoic acid (L-α-amino isoheptanoic acid, L-α-amino isononanoic acid) and 5-chloro-D-tryptophan, of which the amino acids in parenthesis were the replaceable ones at each position. Free amino group in longicatenamycin was shown to be only δ-amino group of ornithine (ε-amino group in lysine) by means of 2,4-dinitrophenylation and hydrolysis. Although partial hydrolysis of this peptide with 6N HCl revealed only a sequence of Lca (α-amino isoalkanoic acid)-Val (Ile)-Orn (Lys), the selective chemical cleavage by oxidation with N-bromosuccinimide followed by Edman degradation clarified the total structure of longicatenamycin as shown below. cyclo (Lca-Val-Orn-HyGlu-ClTrp-Gly) Lca: L-α-aminoisooctanoic acid and its homologs HyGlu: threo-β-hydroxy-L-glutamic acid ClTrp: 5-chloro-D-tryptophan
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寺原 昭, 羽石 達生, 新井 守, 桑野 晴光
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The antifungal metabolite, herbicidin A (C_<23>H_<29>O_<11>N_5) and herbicidin B (C_<18>H_<23>O_9N_5) obtained from Streptmyces saganonensis (Strain No 4075) have a plant growth inhibiting effects against to baryard glass, green panicum, tomato and radish ect., in a concentration 37-300ppm without effect to rice. Basic hydrolysis of herbicidin A affords an unsaturated acid 3 which has been confirmed to be 2-hydroxymethyl-2-butenoic acid, and herbicidin B acid 4. Methanolysis of herbicidin A and B with Amberlyst 15 in methanol affords adenine, and C_<19>H_<28>O_<12> 8 and C_<15>H_<24>O_<10> 5 respectively. On the bases of chemical and physico-chemical evidences of these derivatives, structures of herbicidin A and B have been determined to be nucleosides which consist of adenine and an unusual sugar moiety.
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坂田 完三, 桜井 成, 田村 三郎
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Ezomycin complex, produced by a strain of Streptomyces, is a mixture of novel antifungal antibiotics. We have succeeded in the isolation of four components from the complex, ezomycins A_1 (C_<26>H_<38>N_8O_<15>S・H_2O), A_2(C_<19>H_<26>N_6O_<12>・H_2O), B_1(C_<26>H_<39>N_7O_<17>S), B_2(C_<19>H_<27>N_5O_<14>) and disclosed that A_1 and B_1, the main active components, are new peptidyl pyrimidine nucleosides containing L-cystathionine. Quite recently, structural elucidation of A_1 and A_2 was accomplished in the following way. When hydrolyzed with Dowex 50W (H^+), A_1 (I) liberated L-cystathionine and A_2 (II) as main products. This indicates that I is composed of II and L-cystathionine. Acid hydrolysis of II afforded cytosine and ezoaminuroic acid, C_6H_<11>NO_5. On alkaline hydrolysis I was subjected to β-elimination of ezoaminuroic acid moiety, yielding anhydronucleoside A (IV), C_<13>H_<14>N_4O_8, whose carbohydrate moiety accounts for the remaining unknown 8 carbon atoms. Oxidation of I with 2 molar equivalents of NaIO_4, followed by mild acid hydrolysis, gave 1 molar equivalent of glyoxal, lactam-aminohemiacetal (VIII) and nuclebside A (IX), C_<13>H_<17>N_5O_8. On the basis of the physico-chemical evidences of IV, IX and their derivatives, the structures IV and IX were deduced. Accordingly the structure of A_2 was elucidated as II. VIII was reduced by NaBH_4 to give a compound (XI) which produced L-cystathionine sulfoxide and (S)-α-hydroxy-butyrolactone on acid hydrolysis. I was desulfurized with Raney Ni to liberate alanine. From these facts the structure of A_1 was determined to be I as depicted in Scheme 1.
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古川 稔, 早川 勇夫, 太田 元吉, 板井 昭子, 飯高 洋一
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The structure and absolute configuration of kidamycin C_<39>H_<48>N_2O_9. 1/2 H_2O, an antitumor antibiotic produced by a Streptomyces species, have been elucidated as shown in Fig 4 (1-a) on the basis of spectroscopic, chemical and X-ray crystallographic studies. Methylation of kidamycin triacetate with CH_3I, followed by methanolysis gave triacetylmethoxy kidamycin bis(methyl-ammonium iodide) whose structure was determined as shown in Fig 1 by an X-ray analysis, Kidamycin is convertible by acid into isokidamycin (Fig 5 (2-a)) whose structure was also clarified by an X-ray analysis of its halogeno derivatives. From these results structure of kidamycin was deduced. Kidamycin represents a new class of polycyclic microbial metabolites, possessing a skeleton composed of a pyrone ring-fused anthraquinone as a chromophore and two C-glycosidic amino sugar rings. As for the conformation of amino sugar ring, one is chair and the other is boat. The latter, on isomerization, is rearranged to chair.
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三島 洋, 倉林 正明, 田村 千尋, 佐藤 定男, 桑野 晴光, 斉藤 彰広, 青木 篤
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セッションID: 41
発行日: 1974/10/01
公開日: 2017/08/18
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The milbemycins are the metabolites produced by Streptomyces B-41-146 strain and exhibit a remarkable pesticidal activity against mites such as two-spotted spider mite and citrus red mite, and insects such as rice leaf beetle and tent caterpillar, without phytotoxicity on many variety of crops at effective dosages. Milbemycin α3 and β1 were converted into the urethane derivatives containing a heavy atom, and the structures of which were determined independently by X-ray analysis. On the basis of the established structures of M.α3 and M.β1, those of the other constituents were determined by the chemical correlation and/or the comparison of spectral data (IR, UV,^1H ε ^<13>C NMR and Mass). The structures consist of three basic units: 16-membered lactone, substituted cyclohexene, and spiro ketal system containing two six-membered rings.
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安藤 邦雄, 佐々木 弘, 細川 知良, 縄田 喜治
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セッションID: 42
発行日: 1974/10/01
公開日: 2017/08/18
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Molecular structure and absolute configuration of 4-o-ethyl ascofuranone (C_<23>H_<28>O_5Cl・C_2H_5) were determined by X-ray crystal structure analysis. Crystal structure was solved by the multisolution method. Dihydro-2,2-dimethyl-furan-3-one ring in the molecule adopts an envelope conformation, and the spatial configuration around the asymmetric carbon on the ring is Sinister according to the notation by Cahn, Ingold and Prelog. ORD and CD spectra were consistent with the ketone octant rule which predicted negative Cotton effect for the carbonyl n-π transition. Proton NMR spectra indicated that the ring was rigid, and its conformation in the solution was approximately identical to that in the crystal. All these results are the first stereochemical data on dihydro-2,2-dimethyl-furan-3-one ring in natural product.
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紙谷 孝, 寺地 務, 橋本 真志, 奥 照夫, 中口 修
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セッションID: 43
発行日: 1974/10/01
公開日: 2017/08/18
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The syntheses of new modified β-lactam antibiotics are described. The reaction of disulfide(2a) with nucleophiles in the presence of heavy metal ions leads to new 2β-substituted methyl penicillins(3) and 3β-substituted cephams(5). The same products are also obtained by nucleophilic displacement of 2-bromomethyl penicillin(3a) and 3-bromo-substituted cepham (5a). It seems reasonable to postulate that these reactions proceed via the same intermediate "episulfonium ion(4)". The evidence is described in some details. While, 2-bromomethyl penicillin(3a) is cyclized by strong bases intramolecularly to give a new product(9) which possesses a condensed cyclopropane ring in the molecule. Treatment of (9) with AlBr_3 as a Lewis acid affords a new β-lactam antibiotic (13) as a major product accompanied with a small amount of (14) and (15). However, when TiCl_4 is used, (16) is obtained as a major product. By oxidations of both (15) and (16) with m-chloroperbenzoic acid, a mixture of (17) and (18) is obtained respectively. It is found that various acyl derivatives(20) possess higher antibacterial activities than the corresponding deacetoxy-cephalosporins.
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前田 謙二, 八木沢 尚正, 柴原 聖至, 島崎 正美, 近藤 信一, 梅沢 浜夫, 大野 雅二
原稿種別: 本文
セッションID: 44
発行日: 1974/10/01
公開日: 2017/08/18
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Coformycin (1) is a unique nucleoside, having a moiety of 3,6,7,8-tetrahydroimidazo [4,5-d] [1,3]diazepin-8(R)-ol as the base moiety, and has an interesting biological property which strongly inhibits adenosine deaminase. We wish to report the total synthesis of coformycin starting from a purine ribonucleoside. Thus, 9-β-D-ribofuranosylpurine (3), a naturally occurring nucleoside antibiotic called nebularine, was taken as the starting material, since it was already synthesized. The photoaddition of methanol to 9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)purine (4) was carried out under argone atmosphere and irradiation, affording 9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-6-hydroxymethyl-1,6-dihydropurine (5) which can be used for the ring expansion of the purine moiety. Mesylation of 5 with MsCl in the presence of NaH followed by the solvolysis with t-BuOK afforded synthetic coformycin in good yield. The identity of the synthetic coformycin (1) with the natural one was confirmed by mixture melting point, tlc, and spectroscopic data. The problem of the stereochemistry involved in the total synthesis will be discussed.
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