ANTIBODY CATALYSIS OF ENANTIO- AND DIASTERE-SELECTIVE ALDOL REACTIONS

摘要

Three monoclonal aldolase antibodies, generated against a beta-diketone hapten by reactive immunization, catalyzed rapid and highly enantioselective retro-aldol reactions providing ent-9a-k by kinetic resolution. Compounds 9a, 9g and 9k were resolved in multi-gram quantities using 0.005-0.0004 mol % antibody catalyst. Enantiomerically pure starting materials, 9a-k, are useful synthons for the construction of epothilones A-E (2-6) and their analogs including 13-alkyl derivatives. Previously, the use of compound 9a as a synthon was reported in the preparation of epothilones A-D, 2-5. To further expand this synthon-based strategy, syntheses of epothilone E, 6, 13-methyl epothilone C, 7, and their trans-isomers have been achieved starting from enantiomerically pure thiazole aldols 9g and 9a, respectively, prepared by large-scale antibody catalyzed resolutions.