The cyclohexene compounds may be represented by the formula: in which each Y is independently an alkyl group of 1 to 4 carbon atoms, Z is a hydroxy group, a 2-oxoethyl group, a hydroxyalkyl group of 1 to 3 carbon atoms, an alkoxycarbonyl group of 2 to 5 carbon atoms, or in which R??? is an alkyl radical of 1 to 4 carbon atoms and R??? is an alkane di-yl radical of 2 to 4 carbon atoms or an alkylid