title: Straightforward methodology for the enantioselective synthesis of benzo[a]- and indolo[2,3-a]quinolizidines.
abstract: An enantioselective two-step route to substituted benzo[a]- and indolo[2,3-a]quinolizidines has been developed. It consists of (i) a stereoselective cyclocondensation of a racemic or prochiral delta-oxo(di)ester with either (S)-(3,4-dimethoxyphenyl)alaninol or (S)-tryptophanol in a process involving a dynamic kinetic resolution and/or the differentiation of enantiotopic or diastereotopic ester groups, and (ii) a subsequent stereocontrolled cyclization on the aromatic ring taking advantage of the masked N-acyl iminium ion present in the resulting oxazolopiperidone lactams.
authors.affiliation: Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, 08028-Barcelona, Spain. amat@ub.edu
authors.forename: Mercedes
authors.initials: M
authors.lastname: Amat
authors.forename: Maria M M
authors.initials: MM
authors.lastname: Santos
authors.forename: Oriol
authors.initials: O
authors.lastname: Bassas
authors.forename: Núria
authors.initials: N
authors.lastname: Llor
authors.forename: Carmen
authors.initials: C
authors.lastname: Escolano
authors.forename: Arantxa
authors.initials: A
authors.lastname: Gómez-Esqué
authors.forename: Elies
authors.initials: E
authors.lastname: Molins
authors.forename: Steven M
authors.initials: SM
authors.lastname: Allin
authors.forename: Vickie
authors.initials: V
authors.lastname: McKee
authors.forename: Joan
authors.initials: J
authors.lastname: Bosch
mesh_terms: D000470:Alkaloids / Q000737:chemistry; D001554:Benzene / Q000737:chemistry*; D003500:Cyclization; D007211:Indoles / Q000737:chemistry*; D015394:Molecular Structure; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000737:chemistry; D011807:Quinolizines / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism; D014364:Tryptophan / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: D000470:Alkaloids; D007211:Indoles; D011807:Quinolizines; C012481:phenylalaninol; D010649:Phenylalanine; C069544:tryptophanol; D014364:Tryptophan; D001554:Benzene