Octahydroquinoline Syntesis via Immonium Ion Based Diels-Alder Chemistry: Synthesis of (-)-8a-Epipumiliotoxin C

Article abstract of DOI:10.1021/jo00251a002

A total synthesis of (-)-8a-epipumiliotoxin C has been developed which features an intramolecular immonium ion based Diels-Alder reaction.Cyclocondensation of the immonium ion 8 derived from optically pure aldehyde 2 and ammonium chloride provided two octahydroquinolines 9 and 10, in a ratio of 2.2:1.The formation of 9 and 10 is rationalized on the basis of the chair-like conformations 16 and 17 respectively.Reduction of the double bond in 9 affored (-)-8a-epipumiliotoxin C.