Jl. Charlton et al., SYNTHESIS OF ACETYLENEDICARBOXYLIC ACID-ESTERS AND ASYMMETRIC DIELS-ALDER REACTIONS OF THE BIS(METHYL (S)-LACTYL) ESTER, Canadian journal of chemistry, 73(9), 1995, pp. 1454-1462
A general method has been developed for the preparation of acetylenedi
carboxylic acid esters and applied to the synthesis of both achiral an
d chiral esters. Diels-Alder reactions of one of the chiral esters, th
e bis(methyl (S)-lactyl) ester, with various types of dienes, such as
phenylbutadiene, orthoquinodimethanes, and isobenzofuran, have been in
vestigated. Moderate asymmetric induction was observed in reactions wi
th dienes bearing an alpha-hydroxyl group. In one case, an unusual sol
vent-induced reversal of asymmetric induction was observed.