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Volume 41, Issue 8
Displaying 1-10 of 10 articles from this issue
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Muneo SASAKI, Jiro OSUGI1983 Volume 41 Issue 8 Pages 692-700
Published: August 01, 1983
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThis is a review article mainly on the reaction mechanism and chemical dynamics in solution, which could be revealed by studying pressure effects on reaction rates and equilibria. On a few kinds of organic reactions, it was pointed out that activation volume is unequivocally important to know the rele of solvation on a reaction mechanism and the degree of solvent participation in a transition state. The pressure effect on a primary kinetic isotope effect on a proton/deuteron transfer reaction is a good criterion for tunneling phenomenon.
Recent papers are also reviewed on high-pressure organic synthesis and solid-state polymerization reactions including mechanochemical reactions.View full abstractDownload PDF (1066K) -
Shinkiti KOTO, Naohiko MORISHIMA, Shonosuke ZEN1983 Volume 41 Issue 8 Pages 701-717
Published: August 01, 1983
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSRecent progress in the methods for Ο-glycosylation are reviewed. The topics are summarized in the eleven items : (i) α-Glc type glycosylation, (ii) β -Glc type glycosylation, (iii) α-Man type glycosylation, (iv) β-Man type glycosylation, (v) α-GlcN type glycosylation, (vi) β-GlcN type glycosylation, (vii) 2-deoxy-glycosylation, (viii) ketosylation, (ix) acetal glycosylation (x) the topics relating to ο-glycosylation, and (xi) polysaccharide synthesis.View full abstractDownload PDF (1592K) -
Morio ASAOKA, Hisashi TAKEI1983 Volume 41 Issue 8 Pages 718-727
Published: August 01, 1983
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThis article describes carbon-carbon bond forming reactions utilizing trialkylsiloxy substituted heterocyclic aromatic compounds and their synthetic applications. Siloxyfurans synthesized from buten-4-olides or succinic anhydrides reacted with dienophiles to give corresponding Diels-Alder adducts. In the presence of Lewis acids they also reacted with orthoesters, acetals, α, β-unsaturated ketones, aldehydes, and ketones to give corresponding buten-4-olide derivatives or bislactones.
Similar reactions of siloxyoxazoles synthesized from 2-oxazolin-5-ones are also described.View full abstractDownload PDF (1015K) -
Mitsuaki WATANABE1983 Volume 41 Issue 8 Pages 728-744
Published: August 01, 1983
Released on J-STAGE: January 22, 2010
JOURNAL FREE ACCESSDirected metalation has recently been recognized as an efficient new synthetic methodology for the regiospecific construction of highly substituted aromatic systems. In this review, the utility of the directed metalation strategy for the synthesis of a variety of complex aromatic compounds, especially natural products, is described.View full abstractDownload PDF (1720K) -
Susumu KOBAYASHI1983 Volume 41 Issue 8 Pages 745-754
Published: August 01, 1983
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThe reaction of γ, δ- or δ, ε-unsaturated carboxylic acid with halogen afford halolactone in high yield. This halolactonization reaction generally proceeds in a high stereo- and regiospecific manner. This makes the reaction one of the most important procedures for the functionalization of the carbon-carbon double bond.
This review provides illustrative examples of the synthesis of natural products where halolactonization reaction plays an important role.
Some related reactions are also described.View full abstractDownload PDF (1117K) -
Katsumi KAKINUMA1983 Volume 41 Issue 8 Pages 755-767
Published: August 01, 1983
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSChiral labeling, which is essential to the studies on the mechanism and cryptic stereochemistry involved in the individual enzyme reactions as well as in the complicated biosynthesis of antibiotics and other natural products, has been studied based upon the concept of chirality transfer from carbohydrate derivatives to the key intermediates containing an ethynyl functionality.
D- (6R) - and D- (6S) - (6-2H1) glucose were synthesized for the first time by a totally chemical method. A facile and versatile access to create chirally labeled methylene group was also developed and was effectively utilized for the preparation of chiral glycine and chiral acetic acid with high chiral purity.
Along this line, the biosynthesis of ribostamycin and lankacidins are also discussed from the mechanistic standpoints, which were studied by using various deuterium labeled precursors.View full abstractDownload PDF (1316K) -
Takeshi OHNUMA1983 Volume 41 Issue 8 Pages 768-775
Published: August 01, 1983
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSThe efficient introduction of a vinyl substituent to the α-carbon of various carbonyl groups is an urgent need of organic synthesis, since such vinyl products are available precursors for Cope, oxy-Cope, and Claisen rearrangements. These methods could be further applicable to the synthesis of the medium-sized ring system and, moreover, could be extended to the synthesis of many natural products having vinyl substituents. Recently, a number of vinylation methods of enolizable compounds have been developed by several groups.View full abstractDownload PDF (618K) -
Yoshio KOBAYASHI, Koji TAKANO, Kunio ITABASHI1983 Volume 41 Issue 8 Pages 776-777
Published: August 01, 1983
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSIt was found that alkyl halide-dimethylthioformamide adducts were decomposed with methanol to form the corresponding thiols in high yields. This reaction which occurs in neutral nonaqueous solvents under mild conditions provides a valuable method for the synthesis of the thiols containing some sensitive functional groups.View full abstractDownload PDF (250K) -
Ryohei AIHARA1983 Volume 41 Issue 8 Pages 778
Published: August 01, 1983
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (99K) -
Tatsuo KYUMA1983 Volume 41 Issue 8 Pages 779
Published: August 01, 1983
Released on J-STAGE: November 13, 2009
JOURNAL FREE ACCESSDownload PDF (102K)
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