Enantioselective synthesis of 3,3-disubstituted piperidine derivatives by enolate dialkylation of phenylglycinol-derived oxazolopiperidone lactams.
The stereochemical outcome of the enolate dialkylation of simple phenylglycinol-derived oxazolopiperidone lactams is studied. High stereoselectivities in the generation of the quaternary stereocenter are obtained by the appropriate choice of both the configuration of the starting lactam and the order of introduction of the substituents. The usefulness of the methodology is illustrated by the conversion of some of the dialkylated lactams into known synthetic precursors of alkaloids and by the total synthesis of (-)-quebrachamine.
Amat
Mercedes
M
Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, 08028-Barcelona, Spain. amat@ub.edu
Lozano
Oscar
O
Escolano
Carmen
C
Molins
Elies
E
Bosch
Joan
J
D000478:Alkylation; D004983:Ethanolamines; D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry; D026121:Indole Alkaloids / Q000138:chemical synthesis; D007769:Lactams / Q000737:chemistry*; D010080:Oxazoles / Q000737:chemistry*; D010880:Piperidines / Q000138:chemical synthesis*; D010881:Piperidones / Q000737:chemistry*; D013237:Stereoisomerism
D004983:Ethanolamines; D026121:Indole Alkaloids; D007769:Lactams; D010080:Oxazoles; D010880:Piperidines; D010881:Piperidones; C005332:N-phenylethanolamine; C091897:quebrachamine; D005998:Glycine