Synthesis and stereochemistry of 1-Thiaflavan-4-ols

Abstract

Lithium aluminium hydride or sodium borohydride reduced 1-thiaflavanone, 6-methyl-1-thiaflavanone, and 4'-chloro-1-thiaflavanone to the corresponding 2,4-cis-1-thiaflavan-4-ols. Deamination of 2,4-cis-4-amino-1-thiaflavans with nitrous acid gave rise to the 2,4-trans-1-thiaflavan-4-ols. N.m.r. measurements were used to determine the stereochemistry of these compounds.