Enantioselective synthesis of (+)- and (-)-dihydroepiepoformin and (+)-epiepoformin

reaction: see text] The enantioselective synthesis of both enantiomers of dihydroepiepoformin (1) and (+)-epiepoformin (2) was achieved from (p-tolylsulfinyl)methyl-p-quinols (SR)- or (SS)-3 and (4R,SR)-4, respectively. Key features include the stereocontrolled conjugate addition of AlMe3 to p-quinol 3 and retrocondensation to the ketone functionality, previous to oxidation of the beta-hydroxy sulfoxide moiety of advanced intermediates to the corresponding sulfone.