Asymmetric total synthesis of (R)-α-cuparenone, (S)-cuparene and formal synthesis of (R)-β-cuparenone through Meinwald rearrangement and ring closing metathesis (RCM) reaction

Abstract

Asymmetric synthesis of enantiopure cuparenoid sesquiterpenes (R)-α-cuparenone, (S)-cuparene and a formal synthesis of (R)-β-cuparenone was presented in this article. Meinwald rearrangement of an enantiopure trisubstituted 2,3-epoxy alcohol derivative was the key reaction employed to construct the quaternary streocenter in the target molecules. Ring closing metathesis (RCM) reaction was explored in the final stage of synthesis to access the cyclopentane core of the natural products.