A new synthesis of N-benzoyl L-acosamine

Reaction of (2$\text{R}$,3$\text{S}$)-2,3-(cyclohexylidenedioxy)butanenitrile, derived from ethyl ($\text{S}$)-lactate, with the magnesium enolate of t-butyl acetate gave the corresponding ($\text{Z}$)-β-amino acrylate derivative, which was transformed into N-benzoyl acosamine by acetylation, stereoselective hydrogenation, acidic hydrolysis, and ring-formation followed by reduction with diisobutylaluminium hydride.