title: Stereoselective synthesis of O-tosyl azabicyclic derivatives via aza Prins reaction of endocyclic N-acyliminium ions: application to the total synthesis of (±)-epi-indolizidine 167B and 209D.
abstract: A diastereoselective protocol has been established for the synthesis of 4-O-tosyl piperidine containing hexahydroindolizin-3(2H)-one, hexahydro-1H-quinolizin-4(6H)-one and 1,3,4,10b-tetrahydropyrido[2,1-a]isoindol-6(2H)-one derivatives via the aza-Prins cyclization reaction of cyclic N-acyliminium ions mediated by p-toluene sulphonic acid (p-TSA) under mild conditions. The reaction is highly diastereoselective and gives excellent yields. This method has been applied to an efficient total synthesis of indolizidine alkaloids, (±)-epi-indolizidine 167B and 209D.
authors: Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India. asaikia@iitg.ernet.in.
authors: Anil K
authors: AK
authors: Saikia
authors: Kiran
authors: K
authors: Indukuri
authors: Jagadish
authors: J
authors: Das
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D053961:Azabicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D007212:Indolizines / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: C413205:167B indolizidine; D000470:Alkaloids; D053961:Azabicyclo Compounds; D007212:Indolizines; D000644:Quaternary Ammonium Compounds; C449379:indolizidine 209D