New acyclic apporach to 3-amino-2,3,6-trideoxy-<scp>L</scp>-hexoses: a stereocontrolled synthesis of N-benzoyl<scp>L</scp>-daunosamine

N-Benzoyl L-daunosamine was synthesized stereoselectively starting from O-t-butyldimethylsilyl L-lactaldehyde and methyl propiolate; the crucial step, intramolecular conjugate addition of a carbamoyl amino group of methyl threo-5-carbamoyloxy-4-triethylsilyloxy-(Z)-hex-2-enoate, proceeded with exclusive 1,3-anti diastereoselectivity.