PREPARATION OF ENANTIOMERICALLY ENRICHED BROMOHYDRINS FROM [N-(P-TOLYLSULFONYL)SULFOXIMINO]OXIRANES USING IN-SITU REDUCTION OF ALPHA-BROMO ALDEHYDES

Treatment of enantiomerically pure [N-(p-tolylsulfonyl)sulfoximino]oxi ranes 6 with MgBr2 in the presence of tetrabutylammonium borohydride g ives enantiomerically enriched bromohydrins 3, together with small amo unts of the primary alcohols 11. The bromohydrins 3 are isolated in go od yields with enantiomeric excesses in the range 70% to 91%. This pro cess establishes that alpha-bromo aldehydes have sufficient configurat ional stability to be viable synthetic intermediates.