Reactivity of gamma-hydroxy-alpha,beta-acetylenic esters with amines: facile synthesis of the optically active 4-amino-2(5H)-furanones.

A convenient synthesis of the optically active 4-amino-2(5H)-furanones is discovered by combining an asymmetric alkyne addition to aldehydes and a subsequent aliphatic amine addition. Both steps can be conducted at room temperature and the products are obtained with high enantioselectivity (84-90% ee). The 4-amino-2(5H)-furanones are also found to undergo very facile electrophilic substitution reactions.