Synthesis of (+)-Lepadin B

Significance

Lepadin B was isolated from the tunicate Clavelina lepadiformis. It is a potent blocker of neuronal nicotinic acetylcholine receptors which are involved in disorders such as Alzheimer’s and Parkinson’s diseases and nicotine addiction. The Barbe-Charette synthesis hinges on a ring-closing/ring-opening metathesis sequence to form the cis-fused decahydro­quinoline core.