Reactivity of γ-Hydroxy-α,β-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.