title: Biogenetic syntheses of kopsijasminilam and deoxykopsijasminilam.
abstract: The hexacyclic ketoester 7, derived from cyclization of racemic minovincine (6), was reduced to two C-19 epimeric alcohols 8 and 9. Stereoelectronically controlled fragmentations of corresponding O-sulfonyl derivatives provided, respectively, the hexacyclic enamine 14 and, after oxidation of the olefin 16, the pentacyclic lactam 17 with a brigehead double bond. Formation of a carbamate, introduction of a second double bond at C-16, and conjugate reductive hydroxylation at C-20, or hydrogenation, gave the title products.
authors.affiliation: Department of Chemistry, University of Vermont, Burlington 05405, USA. mkuehne@zoo.uvm.edu
authors.forename: M E
authors.initials: ME
authors.lastname: Kuehne
authors.forename: Y L
authors.initials: YL
authors.lastname: Li
authors.forename: C Q
authors.initials: CQ
authors.lastname: Wei
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D003500:Cyclization; D010084:Oxidation-Reduction; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; C416063:deoxykopsijasminilam; C416062:kopsijasminilam