LDA-mediated domino carbolithiation reactions of vinylidenecyclopropanes with but-3-yn-2-one and 1-phenylprop-2-yn-1-one

A novel domino carbolithiation reaction of vinylidenecyclopropanes 1 with but-3-yn-2-one and 1-phenylprop-2-yn-1-one by treating with LDA in THF was observed to give the corresponding adducts in moderate to good yields. The scope and limitations as well as the plausible mechanism have been discussed on the basis of control experiments.