Syntheses of (S)- and (R)-dihydromethysticin from two yeast-reduction products, which can be prepared from one racemic compound

Abstract

Biologically active (S)-Dihydromethysticin ((S)-1) with high enantiomeric purity (>99%ee) was synthesized from the optically active yeast-reduction product, (1 R,2 S)-methyl 2-hydroxycyclohexyl acetate (2), through the introduction of the 3,4-methylenedioxybenzyl group, Beayer-Villiger oxidation, and conversion to its enolate. Moreover, (R)-Dihydromethysticin ((R)-1) with high enantiomeric purity (>99%ee) was synthesized from the optically active yeast-reduction product, (1 S,5 S)− 2-oxabicyclo[3.3.0]octan-3-one (3), employing the same synthetic method used for (S)-1. The antifungal activity of both these enantiomers against Colletotricum lagenarium and Bipolaris oryzae was found to be weak.