Stannylcuprationof chiral gamma-amino acetylenic esters: stereocontrolled synthesis of 3-tributylstannyl gamma-amino (E)-alkenoates as precursors of 4-stannylated pyrrolinones

4-Tributylstannyl-5-substituted-pyrrolin-2-ones are prepared through the addition of tributylstannyl cyano cuprate to enantiomerically enriched N-protected ?-amino acetylenic esters. The regio- and stereoselectivity of the addition is discussed as a function of the substrates and of the reaction conditions. Cyclization of the (E)-isomers to the corresponding 4-stannylated pyrrolin-2-ones is reported