title: Asymmetric synthesis of tetracyclic benzo[a]quinolizidine targets.
abstract: We report a novel, facile, and asymmetric approach for the synthesis of polycyclic benzo[ a]quinolizidine targets. In the formation of more functionalized derivatives, we have observed the generation of an iminium ether salt intermediate, formed during an unprecedented retro-Diels-Alder/ N-acyliminium cyclization cascade. The iminium ether intermediate was isolated in good yield, characterized by X-ray crystallography, and subsequently applied as a synthetic building block.
authors.affiliation: Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK. s.m.allin@lboro.ac.uk
authors.forename: Steven M
authors.initials: SM
authors.lastname: Allin
authors.forename: Sean N
authors.initials: SN
authors.lastname: Gaskell
authors.forename: Mark R J
authors.initials: MR
authors.lastname: Elsegood
authors.forename: William P
authors.initials: WP
authors.lastname: Martin
mesh_terms: D018360:Crystallography, X-Ray; D003500:Cyclization; D003517:Cyclopentanes / Q000737:chemistry; D054837:Quinolizidines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D003517:Cyclopentanes; D054837:Quinolizidines