Reaction of the tetrachlorocyclopropane (4, X = OH) with 3.2 molecular equivalents of methyllithium at 0-degrees-C leads to an ca. 6:5 mixture of diastereomeric allenes (5). Reaction of (13) with 2.5 mol. equiv. of methyllithium at -105 to -90-degrees-C leads to isomeric but-3-en-1-ols (14). The reactions may be explained in terms of an anion promoted hydrogen shift in an intermediate cyclopropane or vinylcarbene.