title: Stereoselective synthesis of hexahydro-1H-pyrano- and thiopyrano[3,4-c]quinoline derivatives through a Prins cascade cyclization.
abstract: A cascade reaction of (E)-5-(arylamino)pent-3-en-1-ols and thiols with various aldehydes in the presence of 30 mol % BF3·OEt2 in 1,2-dichloroethane at 80 °C affords a novel class of trans-fused hexahydro-1H-pyrano[3,4-c]quinolines and hexahydro-1H-thiopyrano[3,4-c]quinolines in good to excellent yields with high selectivity. The condensation of (Z)-5-(arylamino)pent-3-en-1-ol with aldehydes provides the corresponding cis-fused products under similar conditions.
authors.affiliation: Natural Product Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India. basireddy@iict.res.in
authors.forename: B V Subba
authors.initials: BV
authors.lastname: Reddy
authors.forename: Durgaprasad
authors.initials: D
authors.lastname: Medaboina
authors.forename: B
authors.initials: B
authors.lastname: Sridhar
authors.forename: Kiran Kumar
authors.initials: KK
authors.lastname: Singarapu
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D003500:Cyclization; D008958:Models, Molecular; D015394:Molecular Structure; D000439:Pentanols / Q000737:chemistry*; D011714:Pyrans / Q000138:chemical synthesis* / Q000737:chemistry; D011804:Quinolines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D000439:Pentanols; D011714:Pyrans; D011804:Quinolines; C584913:thiopyrano(3,4-c)quinoline