Asymmetric synthesis of all stereoisomers of 7,11-dimethylheptadecane and 7-methylheptadecane, the female pheromone components of the spring hemlock looper and the pitch pine looper

The asymmetric synthesis of the stereoisomers of 7,11-dimethylheptadecane (1) and 7-methylheptadecane (2) via α-alkylation employing the SAMP/RAMP hydrazone method with high asymmetric induction and good overall yields is described. A mixture of (7S,11R)-1 and (S)-2 is the female-produced sex pheromone of the spring hemlock looper moth (Lambdina athasaria) and the pitch pine looper moth (Lambdina pellucidaria). They are both forest pests in northeastern North America.