Easy selective generation of (lithiomethyl)cyclopropane or homoallyllithium by a chlorine–lithium exchange

The reaction of (chloromethyl)cyclopropane 5 with lithium and a catalytic amount of DTBB (5 mol %) in the presence of different carbonyl compounds [Et2CO, n-Pr2CO, (c-C3H5)2CO, (CH2)5CO, PhCOMe, t-BuCHO, i-PrCHO, PhCHO] as electrophiles in THF at −78 °C leads, after hydrolysis with water, to the corresponding cyclopropyl alcohols 6. However, when the same starting material is lithiated using naphthalene as the arene catalyst in ether at 0 °C and then reacts with the same series of electrophiles, the final hydrolysis with water yields the corresponding unsaturated alcohols 7.