High diastereoselective vinylogous Mannich reaction induced by O-pivaloylated d-galactosylamine as the chiral auxiliary: stereoselective synthesis of 8-arylazocan-2-one

Abstract

The diastereospecific formation of β-N-glycosidically linked α,β-unsaturated δ-amino aldehyde derivatives has been achieved with high yield via a vinylogous Mannich reaction. The reaction was performed by using a O-pivaloylated galactosyl amine as a chiral template and AlCl3 as a promoter in THF. (S)-8-(p-Nitrophenyl) azocan-2-one can be stereoselective synthesized from (S) ethyl 7-galactosylamino-7-(p-nitrophenyl)hepta-2,4-dienoate by sequential hydrogenation of the double bond, cyclic lactam formation, and removal of the N-glycosidic auxiliary under basic conditions.