Partial and complete dichlorocarbenation of conjugated diene hydrocarbons in the presence of the phase-transfer catalyst catamine AB has been studied. It has been shown that at the initial stages of the process (conversion of the reactant olefins below 30%), alkenyl-gem-dichlorocyclopropanes are the main products. In the case of complete carbenation, corresponding bicyclic structures are formed. The structures of the resulting stereoisomers have been described in detail using H-1 and D-13 NMR methods. The relative reactivity of the initial dienes has been determined using a method of competitive kinetics.