1-<(ethoxycarbonyl)oxy>-2-cyclopropylideneethane

N,N-bis(2-cyclopropylideneethyl)-p-toluenesulfonamide

cyclopropylidene-4 methyl-2 butanol-2

ethyl 4-cyclopropylidene-2-<(diphenylmethylene)imino>butanoate