Glycosylation of triterpene alcohols and acids of the lupane and A-secolupane series - Part CVII

A series of 3- and 28-glucosides and glucosyl esters of betulinic acid (1a), 28-hydroxy-3,4-secolupa-4(23,20(29)-dien-3-oic acid (22a), dimethyl ester of 28-hydroxy-2,3-secolup-20(29)-en-2,3-dioic acid (43a), their 20(29)-dihydro derivatives (1b, 22b, 43b) and several other triterpenes of the lupane (12a, 12b) and 3,4-secolupane series (18a, 18b, 32a) has been prepared by reaction of tetra-O-acetyl-alpha-D-glucopyranosyl bromide in acetonitrile in the presence of mercury(II) cyanide and subsequent deacetylation of the obtained tetra-O-acetyl-beta-D-glucopyranosyl derivatives. In several cases attempted glucosylation in the presence of silver silicate afforded predominantly the corresponding 1,2-orthoacetates of alpha-D-glucopyranose.