Reaction of Enol Ethers with Carbenes. X. Ring Opening of 2,2-Dichlorocyclopropyl Phenyl Sulfides

Abstract
The ring opening reactions of six known or new 2,2-dichlorocyclopropyl phenyl sulfides have been carried out with potassium t-butoxide in t butyl alcohol and with pyridine. The products were enynes, butadienes, allenes and, as minor products, α,β-unsaturated aldehydes containing the phenylmercapto group. Reaction of a mixture of cis- and trans-1,1-dichloro-2-methyl-3-phenylmercaptocyclopropane (2) with pyridine gave unchanged trans-isomer. This apparent selectivity is explained on the basis of the steric effects for ring opening.