Asymmetric Syntheses of (-)-ADMJ and (+)-ADANJ: 2-Deoxy-2-amino Analogues of (-)-1-Deoxymannojirimycin and (+)-1-Deoxyallonojirimycin

The asymmetric syntheses of (-)-ADMJ and (+)-ADANJ, the 2-deoxy-2-amino analogues of (-)-1-deoxymannojirimycin and (+)-1-deoxyallonojirimycin, are described herein. Methodology for the ring-closing iodoamination of bishomoallylic amines followed by in situ ring-expansion (via intramolecular ring-opening of the corresponding aziridinium intermediates with a tethered carbamate moiety) to give oxazolidin-2-ones was initially optimized on a model system. Subsequent application of this methodology to two enantiopure bishomoallylic amines (which were produced via aminohydroxylation of an alpha,beta-unsaturated ester, partial reduction, and reaction of the corresponding aldehyde with vinylmagnesium bromide) also proceeded with concomitant N-debenzylation to afford the corresponding diastereoisomerically pure (>99:1 dr) oxazolidin-2-ones. Subsequent deprotection of these enantiopure templates gave (-)-ADMJ and (+)-ADANJ as single diastereoisomers in 16% and 24% overall yield, respectively.