Thiopyran route to polypropionates: An efficient synthesis of serricornin

摘要

The synthesis of serricornin [(4S, 6S, 7S)-7-hydroxy-4,6-dimethylnonan- 3-one], a sex pheromone produced by the female cigarette beetle (Lasioderma serricorne F.), in seven steps from readily available racemic 1,4-dioxa-8- thiaspiro-[4.5] decane-6-carboxaldehyde (6) is described. The key steps include enantioselective aldol reaction of 6 with tetrahydrothiopyran-4- one catalyzed by 5-[(2S)-pyrrolidine-2-yl]-1H- tetrazole to fabricate the tetrapropionate skeleton, stereoselective (LiBu3BH)-Bu-s reduction of the resulting aldol adduct, Barton-McCombie deoxygenation, and Raney nickel desulfurization.