Total synthesis of the Amaryllidaceae alkaloid clivonine

Two syntheses of the Amaryllidaceae alkaloid clivonine (1) are described. Both employ previously reported 7-arylhydrindane 6 as an intermediate but differ in the method employed for subsequent introduction of what becomes the ring-B lactone carbonyl carbon (C7). The synthesis featuring a Bischler–Napieralski reaction for this transformation constitutes the first asymmetric synthesis of natural (+)-clivonine. Crystal structures for compounds (±)-13, (±)-16, (−)-20 and (±)-28 are also reported

Total synthesis of the lycorenine-type amaryllidaceae alkaloid (±)-clivonine via a biomimetic ring-switch from a lycorine-type progenitor

A fully diastereoselective total synthesis of the lycorenine-type Amaryllidaceae alkaloid (±)-clivonine is reported via a route that employs for the first time a biomimetic ring-switch from a lycorine-type progenitor, thereby corroborating experimentally the biogenetic hypothesis first expounded for these compounds by Barton in 1960