Cyclopropane derivatives were formed from two monoolefins and three dienes by the method of Simmons and Smith12 using diiodomethane and zinccopper couple. Although the exact nature of the reactive intermediate has not been determined, it is useful to consider that cyclopropane formation occurs via a carbene me~ hanism.~ The products obtained from bicyclohexylidene, &pinene, and 1, 6cyclooctadiene were dispiro [5.1.-5.01 tridecane (I), 6 ...