Convenient Synthesis of 3,3-Dimethylcyclohexylideneacetaldehyde, a sex attractant of the male Boll Weevil

Abstract
In a previous communication1 we reported on the synthesis of 3,3-dimethylcyclohexylideneacetaldehyde (5a), an important component of the sex pheromone complex of the male Boll Weevil. A key step in this synthesis involved the simultaneous removal of halogen and a double bond from an intermediate poly unsaturated aldehyde by selective reduction. As a part of our investigations on the Vilsmeier formylation of vinylcyclopropanes and dienes2, we have found an easy route to aldehyde 4a, and we now show that this aldehyde can serve as an excellent synthon for the preparation of 3,3-dimethylcyclohexylideneacetaldehyde (5a).