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Volume 44, Issue 3
Displaying 1-10 of 10 articles from this issue
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Haruki NIWA, Kiyoyuki YAMADA1986 Volume 44 Issue 3 Pages 180-190
Published: March 01, 1986
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThree potent neurotoxins of plant origin, picrotoxinin 1, coriamyrtin 2, and tutin 3, and a toxic, bitter principle of a scale insect, asteromurin A 69 are highly oxygenated sesquiterpenoids of the picrotoxane-type.
Stereocontrolled total synthesis of these four natural products in optically active form is described using a functionalized cis-hydrindane 50 as a common intermediate. Double cyclization of deacetalized products of cyclohexenones 42 gave tricyclic compounds of the isotwistane skeleton 43, which were subsequently transformed into a ketone 45. Utilizing the bridgehead hydroxylation of the bicyclo [3. 2. 1] octan-2-one part of the isotwistane skeleton in the ketone 45, a bicyclic compound 47 was synthesized and further converted to the cis-hydrindane 50, the common intermediate for the synthesis of picrotoxane sesquiterpenoids. After optical resolution, the cis-hydrindane (+) -50 was converted to a cyclic ether (-) -53, which, in turn, was transformed into (-) -picrotoxinin 1, (+) -coriamyrtin 2, (+) -tutin 3, and (+) -asteromurin A 69.View full abstractDownload PDF (991K) -
Toshio SUZUKI1986 Volume 44 Issue 3 Pages 191-205
Published: March 01, 1986
Released on J-STAGE: January 22, 2010
JOURNAL FREE ACCESSThis article describes the synthetic studies on various types of natural products and its relative compounds which include reserpine, yohimbine, dehydrocorynantheol, antirhine, prostaglandin analogues, secologanin, semburine and 11-ketosteroid, using the common synthon easily derived from symmetrical compounds such as maleic anhydride and D-mannitol as illustrated in Fig.1 and 2.View full abstractDownload PDF (1421K) -
Mitsuhiro KINOSHITA, Masaya NAKATA1986 Volume 44 Issue 3 Pages 206-218
Published: March 01, 1986
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSConvergent and enantiospecific total syntheses of rifamycin W ansa-chain compound (48) and erythronolide A (61) were achieved by the use of a “two-stage coupling” process, which was developed for stereocontrolling the carbon chain connections in the synthesis. The new coupling process consists of the first stage of addition reaction of appropriate vinyllithio compounds to 2-methyl-substituted aldehydes and the second stage of homogeneous hydrogenation with Wilkinson's catalyst of the major “Cram” type of addition products. In the practical total syntheses of 48 and 61, the process gave predominantly “Cram” (syn) -anti type of coupling products to provide the proper chiral sequences of 48 and (9 S) -9-dihydroerythronolide A which was an important pre-cursor of 61. Principal stereochemical features of this process are described for using it effectively in natural product synthesis.View full abstractDownload PDF (1369K) -
Masaaki UEKI1986 Volume 44 Issue 3 Pages 219-228
Published: March 01, 1986
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSSince the discovery of two endogenous opioid peptides, Met-and Leu-enkephalins, a lot of works have been done to develop better analgesics without side-reactions. By now many highly potent analogues of enkephalins have been designed and synthesized. But, pure analgesics have not so far been obtained. It is mainly because of the complexity of opioid ligands and their interactions with multiple receptors. In addition recent knowledge of enhancing effects of peptidase inhibitors on the potency of opioid peptides prompts us to reexamine all the accumulated pharmacological data.View full abstractDownload PDF (1196K) -
Mitsuo SEKINE, Tsujiaki HATA1986 Volume 44 Issue 3 Pages 229-244
Published: March 01, 1986
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSSynthesis of phosphorothioates and their properties are reviewed from the standpoint of organophosphorus chemistry. Inherent synthetic problems in the P-S bond formation are described. Several methods for the synthesis of nucleoside phosphorothioates are introduced and their application to oligonucleotide synthesis is also described from various aspects. Especially, the versatile utility of the bis (phenylthio) phosphoryl group, which can be readily introduced to nucleoside hydroxyls, is shown with several successful examples of the synthesis of DNA and RNA fragments.View full abstractDownload PDF (1648K) -
Toshio HAYASHI1986 Volume 44 Issue 3 Pages 245-257
Published: March 01, 1986
Released on J-STAGE: January 22, 2010
JOURNAL FREE ACCESSThis review summarized the strategy and use of allylic and pentadienyl dithiocarbamates in organic synthesis, and focuses on a new [3, 3] -sigmatropic rearrangement of the α-alkylated allylic dithiocarbamates to the γ-alkylated ones with 100 % trans-selectivity, which are followed by the realkylation, allylation, or functional group interconversion at the newly created a-methylene group. Thus, these reagents have a highly potential utility in the stereoselctive syntheses of monoenes, dienes, trienes, and tetraenes, and are also used for the preparation of allylic halides and alcohols, α, β-unsaturated aldehydes, vinyl thiiranes, acyclic terpenes, and a variety of silyl reagents.View full abstractDownload PDF (1138K) -
Osamu SAEGUSA1986 Volume 44 Issue 3 Pages 258-261
Published: March 01, 1986
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (484K) -
Fukashi HORIUCHI1986 Volume 44 Issue 3 Pages 262-263
Published: March 01, 1986
Released on J-STAGE: January 22, 2010
JOURNAL FREE ACCESS -
Sotoyuki KIRITANI1986 Volume 44 Issue 3 Pages 264-265
Published: March 01, 1986
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (208K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]1986 Volume 44 Issue 3 Pages 266
Published: March 01, 1986
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (152K)
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