Free radical annulation of dichlorocyclobutanones with sequential ring expansion

Article abstract of DOI:10.1016/0040-4020(95)00093-N

A new synthetic sequence that adds the elements of ketene across the termini of a 1,5-diene is described. Dichlorocyclobutanone adducts from reaction of dichloroketene with 1,5-dienes undergo intramolecular free radical annulation. Lewis acid-promoted rin