α-cyclopropylidene carbinols (the 1,2-addition product). Addition of methyl-lithium and lithium dimethylcuprate lead to the expected 1,2- and 1,4-additionproducts, respectively. The comparison of these results and those corresponding to α-isopropylidene-ketones confirms the higher tendency of α-cyclopropylidene-ketones to give 1,4-additionproducts; the measurement of polarographic reduction potentials confirms