Enantioselective preparation of alkyl alkylsulfanylmethyl sulfoxides and 4,5-dihydroisoxazoles from alkanesulfinates of 1,2 : 5,6-di-O-isopropylidene-D-glucose

Abstract

Reaction of (R)- and (S)-alkanesulfinates of 1,2 : 5,6-di-O-isopropylidene-D-glucose (DAG) with methylsulfanylmethyllithium produces their corresponding dithioacetal mono-S-oxides with enantiomeric excesses ranging from 95 to 100%. On the other hand, exo-metallation of 3-methyl-4, 5dihydroisoxazoles and their subsequent reaction with (R)- and (S)-alkanesulfinates of DAG produces optically active 3-ethylsulfinylmethyl-4,5-dihydroisoxazoles.