Erythrina and related alkaloids.

The chemistry of Erythrina and related alkaloids from 1996 through to mid-2009 has been reviewed, with a particular focus on the preparation of Erythrina alkaloids possessing an aromatic D ring. A number of synthetic approaches to alkaloids bearing an aromatic D ring have been reported, including some asymmetric routes. Recent studies have explored strategies toward Erythrina alkaloids possessing a nonaromatic D ring, although, as yet, few total syntheses have been published.