Brian L. Buckwalter

β, γ-Unsaturated Carbonyl Compounds

Abstract 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.

Methyl β-(2-Methyl-5-Oxocyclopentenyl-) Propionate and Ethyl 3-Methyl-6-Oxohepta-2, 4-Dienoate

Abstract As part of a broad study of γ-diketone synthesis2 by way of cyclopropanation of enol ethers or esters with diazoacetic ester or diazomethyl ketones followed by hydrolytic cyclopropane scission it became of interest to learn whether ester carbonyl groups within interacting distance of the diazocarbonyl unit would interfere in the cyclopropanation step and whether furans can be made to undergo cyclopropanation like enol ethers. The following two investigations were undertaken to resolve these issues.