β, γ-Unsaturated Carbonyl Compounds

It has been shown recently that β-oxycyclopropyl carbinols are transformed readily into β, γ-unsaturated keto systems on mild acid treatment.1 The following description of the α, α-dialkylation of an aldehyde and of a ring enlargement process illustrates further the great usefulness of the β-oxycyclopropylcarbinyl unit in organochemical synthesis.