General approach to synthesis of chiral branched hydrocarbons in high configurational purity.

Configurationally pure (>99.6%) α-methylalkanoic acids have been employed to prepare chiral hydrocarbon semiochemicals. The stereoisomers of the following compounds were synthesized: 13-methylhentriacontane, 15-methyltritriacontane, and 15,19-dimethyltritriacontane. The first compound was identified earlier as a kairomone of the corn earworm while the other two are sex excitants of the stable fly. The methods described have broad applicability in asymmetric synthesis.