cis- and trans-Azetidin-2-ones from nitrones and copper acetylide

Abstract

The reaction between nitrones and copper acetylides in pyridine yields cis- and trans-azetidinones. Deuteriation and isomerisation studies indicate that the trans-compound is produced from the initially formed cis-isomer and that the amount of cis-product may be increased by using non-basic solvents. Lactams with aromatic, aliphatic, and ethoxycarbonyl substituents may be obtained from appropriately substituted acetylenes, and the use of cyclic nitrones leads to bicyclic compounds.