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Volume 38, Issue 4
Displaying 1-7 of 7 articles from this issue
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Eiichi FUJITA1980 Volume 38 Issue 4 Pages 333-350
Published: April 01, 1980
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSSynthetic works on some macrocyclic alkaloids with which the author have been concerned are reviewed. In the section 2, syntheses of bisbenzylisoquinoline alkaloids, i. e. tetrandrine 11, isotetrandrine 8, phaeanthine 20, ο-methylthalicberine 16, and (±) -cycleanine 12, are described. In the section 3, syntheses of the lactonic alkaloids isolated from the American Lythraceae plants are outlined and the details of our synthesis of lythranidine 45, a Japanese Lythraceae alkaloid isolated from Lythrum anceps by us, are also described. The fourth section deals with synthesis of the spermidine and speimine alkaloids. They are (±) -oncinotine 101, (±) -neo-oncinotine 115, pseudo-oncinotine 117, (±) -tetrahydro-lunaridine 118, etc. In addition, the “zip” reaction exploited by Schmid et al., our new synthetic method for macrocylic dilactams, and its attempted application to the syntheses of lunarine 5 and codonocarpine 133 are also introduced.View full abstractDownload PDF (1919K) -
Kazuhiro MARUYAMA, Yasuo KUBO1980 Volume 38 Issue 4 Pages 351-360
Published: April 01, 1980
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSPhotochemical reactions related on the synthesis of medium- and macrocyclic compounds are reviewed. This article is constructed by the following chapters : (i) photochemistry of p-benzophenone carboxylic esters, (ii) photo-cycloaddition of intramolecular two identical chromophores, (iii) photo-cyclization of intramolecular electron donor-acceptor pairs, (iv) α-cleavage reaction of carbonyl compounds, (v) electrocyclic reactions, and (vi) others.View full abstractDownload PDF (1128K) -
Yukito MURAKAMI1980 Volume 38 Issue 4 Pages 361-371
Published: April 01, 1980
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSCyclodextrins, crown ethers, cyclophanes have been cited as macrocyclic enzyme models. Cyclodextrins increase the recognition ability toward guest molecules by the following modifications; capping the cavity at one end, and connecting two cyclodextrin molecules with bridging components (duplex cyclodextrin). Upon introduction of two functional groups on the cavity edge, cyclodextrins exercise bifunctional catalysis. β-Cyclodextrin exhibits chiral recognition ability toward some sulfoxides. Crown ethers incorporate ammonium salts primarily by hydrogen bonding (+NH…O) and electrostatic (N+…O) interactions. These compounds provide chiral recognition sites by appropriate molecular design. [20] - and [10. 10] paracyclophanes provide a hydrophobic binding site much more effective than cyclodextrins and exercise various bifunctional catalyses in the deacylation of hydrophobic carboxylic esters. Azaparacyclophanes bearing multiple alkyl chains (octopus-cyclophanes) incorporate various substrates by the hydrophobic-electrostatic interaction of induced-fit type. A cyclophane having two dihydronicotinamide moieties as the skeleton components enhanced reduction of a carbonyl compound. Cyclophanes can be used not only as hydrolase models but also as oxidoreductase models.View full abstractDownload PDF (1546K) -
Yoshihiko ITO, Takeo SAEGUSA1980 Volume 38 Issue 4 Pages 372-380
Published: April 01, 1980
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThis paper describes a series of reactions of silyl ethers of enols and cyclopropanols with metal salts, in which metal enolates and metal cyclopropoxides may be assumed as key intermediates : (i) Silyl enol ethers are reacted with Ag2O in DMSO to give 1, 4-diketones. (ii) Silyl enol ethers are reacted with CuCl2 in DMF and FeCl3 in acetonitrile to give α-chloroketones. (iii) Silyl cyclopropyl ethers are reacted with FeCl3 in DMF to afford β-chloroketones which are derived from ring-opening. Especially, in the reaction of 1-trimethylsilyloxybicyclo [n. 1.0] alkanes with FeCl3, the bridging bond is regioselectively cleaved to produce β-chlorocycloalkanones. (iv) Silyl enol ethers of pinacolone and camphor are reacted with PdCl2 (PhCN) 2 to afford air-stable Pd (II) complexes, which react with ethylene and butadiene by an addition-elimination mechanism to lead carbon-carbon bond formation at the α-carbon of ketone. PdCl2 (PhCN) 2 promotes intramolecular cyclization of 2-trimethylsilyloxy-5-substituted-1, 5-hexadienes to give σ- (1-substituted-3-oxocyclopentyl) methylpalladium (II) complexes, which can be reacted with a variety of olefins to afford 3, 3'-disubstituted cyclopentanones.View full abstractDownload PDF (963K) -
Takeshi NAKAI, Koichi MIKAMI1980 Volume 38 Issue 4 Pages 381-394
Published: April 01, 1980
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThe present review surveys recent application of sigmatropic rearrangements to ring enlargement reactions leading to medium ring compounds. The rearrangements concerned are thermally-allowed [2, 3] - and [3, 3] sigmatropic rearrangements as well as related [1, 3] sigmatropic shift.
The 1st chapter deals with a general strategy for applications of these rearrangements to synthesis of medium ring compounds via two- or more-carbon ring enlargements.
The 2nd chapter describes various methods for ring enlargement reactions via [3, 3] sigmatropic rearrangements. The sigmatropic shifts concerned include Cope, oxy-Cope and its variants, Claisen rearrangements, and tandem sigmatropic rearrangements. In particular, applications of these approaches to the synthesis of germacrene-type sesquiterpenoids are discussed.
The 3rd chapter deals mainly with ring enlargement reactions via [1, 3] sigmatropic shifts which are closely related oxy-Cope rearrangements. Ring enlargements via photochemical [1, 3] acyl shifts are also described.
The 4th chapter describes various methodologies via [2, 3] sigmatropic rearrangements. The rearrangements. concerned include Sommelet-Hauser type rearrangements in both N- and S-ylide systems and [2, 3] Wittig rearrangements. In particular, repeatable [2, 3] sigmatropic rearragements of S-ylides are shown to be quite useful for ring-growing reactions.View full abstractDownload PDF (1520K) -
Satoshi OMURA, Hideo SAKAKIBARA1980 Volume 38 Issue 4 Pages 395-414
Published: April 01, 1980
Released on J-STAGE: January 22, 2010
JOURNAL FREE ACCESSMany derivatives of 14-membered macrolides such as erythromycin and oleandomycin have been obtained by chemical modification. This review describes the method of synthesis, the biological activity of these derivatives and the structure-microbial activity relationship. The improvement of pharmacological properties have been achieved by acylation of the hydroxyl group existing in the macrolide molecules. Among the compounds modified on the hydroxyl group at C-11, -2′ and -4″ the carbonyl group at C-9, desosamine and cladinose in erythromycin molecule, the modification at the C-9 carbonyl group exhibited outstanding activity against erythromycin resistant organisms.View full abstractDownload PDF (2234K) -
Yoshiharu KATAOKA, Kaoru HARADA1980 Volume 38 Issue 4 Pages 415-419
Published: April 01, 1980
Released on J-STAGE: January 22, 2010
JOURNAL FREE ACCESSα, α'-IDCAs have a stereochemically interesting structure and mainly been used for ligands in complex chemistry. But naturally occurring α, α'-IDCAs (Octopine, Nopaline, Lysopine) have been isolated from the crown gall tumors which are incited by Agrobacterium tumefaciens in plant tissues. An introduction to recent chemical and biological studies was abstracted.View full abstractDownload PDF (615K)
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