Enantioselective synthesis of piperidine, indolizidine, and quinolizidine alkaloids from a phenylglycinol-derived delta-lactam.
Starting from a common lactam, (3R,8aS)-5-oxo-3-phenyl-2,3,6,7,8,8a-hexahydro-5H-oxazolo[3,2-a]pyridine (1), or its enantiomer, the enantioselective synthesis of 2-alkylpiperidines and cis- and trans-2,6-dialkylpiperidines is reported. The potential of this approach is illustrated by the synthesis of the piperidine alkaloids (R)-coniine, (2R,6S)-dihydropinidine, (2R,6R)-lupetidine, and (2R,6R)-solenopsin A, the indolizidine alkaloids (5R,8aR)-indolizidine 167B and (3R,5S,8aS)-monomorine I, and the nonnatural base (4R,9aS)-4-methylquinolizidine.
Amat
Mercedes
M
Laboratory of Organic Chemistry, Faculty of Pharmacy, University of Barcelona, 08028-Barcelona, Spain. amat@farmacia.far.ub.es
Llor
Núria
N
Hidalgo
José
J
Escolano
Carmen
C
Bosch
Joan
J
D000470:Alkaloids / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D007212:Indolizines / Q000737:chemistry*; D007769:Lactams / Q000737:chemistry*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010880:Piperidines / Q000138:chemical synthesis*; D011807:Quinolizines / Q000138:chemical synthesis*; D013237:Stereoisomerism
D000470:Alkaloids; D007202:Indicators and Reagents; D007212:Indolizines; D007769:Lactams; D010880:Piperidines; D011807:Quinolizines; C002351:Solenopsin A