Total synthesis of (±)-clivonine

Abstract

Clivonine is a lycorenine-class Amayllidaceae alkaloid with insect anti-feedant activity. Biosynthetically, it is presumed to be derived from a lycorine class progenitor through the lactam to lactone exchange reaction which involves 180o bond-rotation of C12a-C12b. Despite its natural abundance and interesting biological activities, only a few synthetic studies have been reported. For further application of our 2-pyrone chemistry to the target-oriented synthesis, we have envisaged the Diels-Alder reaction of 2-pyrone with suitably functionalized styrene dienophile would provide the key intermediate which can be readily transformed to clivonine as well as its congeners clivonidine, cliviasine, and nobilisine.