A cationic cyclisation route to prenylated indole alkaloids: synthesis of malbrancheamide B and brevianamide B, and progress towards stephacidin A

The synthesis of the prenylated indole alkaloids, malbrancheamide B and brevianamide B have been accomplished, starting with a prenylated proline derivative created using the Seebach 'self-reproduction of chirality' method, and using a cationic cascade sequence as the key step to form late-stage bridged diketopiperazine intermediates. (C) 2010 Elsevier Ltd. All rights reserved.