Stereoselective, synthesis of new enantiomenrically enriched N-protected gamma-amino acetylenic esters

A new class of differently protected chiral ?-amino acetylenic esters have been synthesized using natural occurring amino acids as chiral source. Enantiomerically enriched propargylamines or vinyldibromides have been treated with BuLi at low temperature affording, after carboxylation, enantiomerically enriched derivatives of alkynologous amino esters