Asymmetric total synthesis of (1S,2S,4S)-β-elemene.

Abstract

Elemenes are sesquiterpene natural products extracted from Chinese medicinal herbs and have been used as an important antitumor drug in China. Here, we report the first stereoselective total synthesis of (1S,2S,4S)-β-elemene using (R)-carvone as a chiral pool starting material. The isopropenyl moiety was achieved in a highly stereoselective manner through 1,4-Michael conjugate addition. The following transformations like regio- and stereoselective aldol condensation, Wittig olefination have been employed as the key steps, resulting in a concise total synthesis of (1S,2S,4S)-β-elemene. Our accomplishment will allow further biological investigations of this natural product and open opportunities for developing a new potentially promising antitumor drug.