Preparation and X-ray crystal and molecular structure of 6-bromopyrrolizin-3-one

Abstract

The X-ray crystal structure of 6-bromopyrrolizin-3-one (2) shows that the lactam unit has a long C–N bond and a short CO bond, although the molecule as a whole is planar. By comparison with data for model compounds it appears that the two rings behave independently, save for a reduced amount of amide-like interaction typical of N-acylazoles. There is no evidence for cyclic delocalisation of the resulting 8π-electron system.