Straightforward methodology for the enantioselective synthesis of benzo[a]- and indolo[2,3-a]quinolizidines.
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.
Amat
Mercedes
M
Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, 08028-Barcelona, Spain. amat@ub.edu
Santos
Maria M M
MM
Bassas
Oriol
O
Llor
Núria
N
Escolano
Carmen
C
Gómez-Esqué
Arantxa
A
Molins
Elies
E
Allin
Steven M
SM
McKee
Vickie
V
Bosch
Joan
J
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
D000470:Alkaloids; D007211:Indoles; D011807:Quinolizines; C012481:phenylalaninol; D010649:Phenylalanine; C069544:tryptophanol; D014364:Tryptophan; D001554:Benzene