M. Shimizu et al., ENANTIOSELECTIVE ESTERIFICATION OF CYCLIC DICARBOXYLIC ANHYDRIDES USING CHIRAL AMINO-ALCOHOLS AS AUXILIARIES, Bulletin of the Chemical Society of Japan, 66(7), 1993, pp. 2128-2130
Cyclic dicarboxylic anhydrides were enantioselectively esterified with
the complex formed from cinchonidine, diethylzinc, and methanol, and
the half-esters obtained were readily transformed into lactones via re
duction and dehydration.