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 ...
