Enantioselective synthesis of natural biologically active ivaide A: 1,3-di-(R)-beta-hydroxy-glyceride glycerol

The natural 1,3-di-beta-hydroxy-glyceride glycerol ivaide A 1 from Ajuga iv a has been synthesised by diacylation of dihydroxyacetone with 3-hydroxyhex adecanoic acid, followed by reduction to the corresponding glycerol derivat ive. The enantiomerically pure (R)-beta-hydroxyhexadecanoic ester intermedi ate 6 was obtained by a coupling reaction of an ethylacetoacetate dianion a nd the corresponding bromoalkyl, followed by the known reduction of the res ulting beta-ketoester 5 by fermenting baker's yeast. (C) 1999 Elsevier Scie nce Ltd. All rights reserved.