SYNTHESIS OF S-(+)-HYDROPRENE

A novel path to S-(+)-hydroprene (1) starting from the technical grade S-(+)-dihydromyrcene (2, e.e. greater-than-or-equal-to 50%) is propos ed. The latter was selectively transformed into S-3,7-dimethyloctanal (5) in three steps including hydroalumination. The reactions of 5 with allyl- or methallylmagnesium chloride followed, respectively, either by oxygenation in the presence of PdCl2/CuCl or by ozonolysis, afford SE-6,10-dimethyl-3-undecen-2-one (7) which was treated with ethoxyethy nylmagnesium bromide to give the title juvenile hormone analogue in ap proximately 23% overall yield.