Facile synthesis of two diastereomeric indolizidines corresponding to the postulated structure of alkaloid 5,9E- 259B from a Bufonid toad (Melanophryniscus)

• Angela Nelson,
• H. Martin Garraffo,
• Thomas F. Spande,
• John W. Daly and
• Paul J. Stevenson

Beilstein J. Org. Chem. 2008, 4, No. 6, doi:10.1186/1860-5397-4-6

• the C5 chain gives rise to the base peak, identifying the mass of the C5 substituent. The resulting cation undergoes a retro Diels-Alder fragmentation losing an alkene thus identifying the mass of the C8 substituent. Once the gross structure has been assigned, analysis of the vapor-phase infrared