Divergent Asymmetric Total Synthesis of All Four Pestalotin Diastereomers from (R)-Glycidol.

ABSTRACT: All four chiral pestalotin diastereomers were synthesized in a straightforward and divergent manner from common (R)-glycidol. Catalytic asymmetric Mukaiyama aldol reactions of readily-available bis(TMSO)diene (Chan's diene) with (S)-2-benzyloxyhexanal derived from (R)-glycidol produced a syn-aldol adduct with high diastereoselectivity and enantioselectivity using a Ti(iOPr)4/(S)-BINOL/LiCl catalyst. Diastereoselective Mukaiyama aldol reactions mediated by catalytic achiral Lewis acids directly produced not only a (1'S,6S)-pyrone precursor via the syn-aldol adduct using TiCl4, but also (1'S,6R)-pyrone precursor via the antialdol adduct using ZrCl4, in a stereocomplementary manner. A Hetero-Diels-Alder reaction of similarly available mono(TMSO)diene (Brassard's diene) with (S)-2-benzyloxyhex

SUBMITTER: Moriyama M 

PROVIDER: S-EPMC7024299 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature