Affiliation:
1. Faculty of Medicine and Health University of New England Elm Avenue Armidale 2351 Australia
Abstract
AbstractA ring‐expansion process for the biomass derivative Cyrene obtained from levoglucosenone has been developed using gem‐dihalocyclopropanes as intermediates. The process involves conversion of Cyrene to an enamine, reaction with an in situ generated dihalocarbene, and then ring‐opening. Competition between endocyclic and exocyclic olefinic products was switchable using solvent and temperature, and ring‐expanded alkenyl halides were obtained in 50–64 % yield from Cyrene. Under extended heating, dehalogenation occurred giving homologated levoglucosenone in 25 % overall yield from Cyrene in 3 steps.