A method for the manufacture of the four geometric isomers of 4(2-butenylidene)-3,5,5-trimethyl-2-cyclohexen-1-one is provided. The process comprises pyrolyzing a compound of the formula ##STR1## wherein R represents lower-alkyl-oxycarbonyl, aryl-oxycarbonyl, or, preferably, lower-alkanoyl, benzoyl or substituted benzoyl.
提供一种制造4(
2-丁烯基亚甲基)-3,5,5-三甲基-
2-环己烯-1-酮的四种几何异构体的方法。该过程包括热解公式##STR1##的化合物,其中R代表低烷氧羰基,芳基氧羰基或更好地,低脂肪酰基,苯甲酰基或取代苯甲酰基。