Synthesis

Simple and Efficient Stereoselective Synthesis of (Z)-and (E)-Alkylidene 2, 3-Dimethoxybutenolides from L-Ascorbic Acid and D-Isoascorbic Acid

MA Khan, H Adams

Index: Khan, M. Akram; Adams, Harry Synthesis, 1995 , # 6 p. 687 - 692

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Citation Number: 17

Abstract

Reactions of 2, 3-di-O-methyl-5, 6-di-O-tosyl-L-ascorbic acid (Sb) and 2, 3-di-O-methyl-5, 6- di-O-tosyl-D-isoascorbic acid (11) with excess of carbon, oxygen and nitrogen nucleophiles produced y-(Z)-and (E)-alkylidene-2, 3-dimethoxybutenolides 6a—e and 12 a—d, respectively, in good yields. The formation of the reaction products 6a—e and 12 ad has been rationalised through the involvement of two reaction processes. The ditosylates ...