A Concise, Protection-Free and Divergent Approach for the Enantioselective Syntheses of Two Pheromonal Epoxide Components of the Fall Webworm Moth and Other Species
On the basis of Zhou’s modified Sharpless asymmetric epoxidation, sequential coupling reactions, and a divergent strategy, the protection-free syntheses of two main pheromonal components 1 and 5, found in the fall webworm moth, Hyphantria cunea, and other species have been accomplished in 10 steps (for two compounds). The overall yields are 31% for 1, 28% for 5, and 25% for both 1 and 5, respectively
A concise synthesis of the sexpheromones of elm spanworm as well as painted apple moth has been achieved. The key steps were the alkylation of acetylide ion, Sharpless asymmetric epoxidation and Brown’s P2-Ni reduction. This approach provided the sexpheromone of the elm spanworm (1) in 31% total yield and those of the painted apple moth (2, 3) in 26% and 32% total yields. The ee values of three final