Diastereoselective nitrenium ion-mediated cyclofunctionalization: total synthesis of (+)-castanospermine.
The asymmetric total synthesis of the α-glucosidase inhibitor (+)-castanospermine is reported. The central theme in our approach to this polyhydroxylated alkaloid is the simultaneous generation of the piperidine ring and the C-1/8a erythro stereodiad through the diastereoselective, oxamidation of an unsaturated O-alkyl hydroxamate. This process is believed to proceed sequentially via singlet acylnitrenium and aziridinium ion intermediates.
Bowen
Edward G
EG
Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, United States.
Wardrop
Duncan J
DJ
D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D002384:Catalysis; D003500:Cyclization; D065089:Glycoside Hydrolase Inhibitors; D007212:Indolizines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D007477:Ions; D015394:Molecular Structure; D013237:Stereoisomerism; D054836:Indolizidines
D000470:Alkaloids; D065089:Glycoside Hydrolase Inhibitors; D007212:Indolizines; D007477:Ions; C037806:castanospermine; D054836:Indolizidines