Syntheses of Apogalanthamine Analogues as α-Adrenergic Blocking Agents. XII. : Syntheses and Stereochemistry of Methoxy and Methylenedioxy Derivatives of 8-Hydroxy-5, 6, 7, 8-tetrahydrodibenz-[c, e]azocines

Abstract

8-Hydroxy-5, 6, 7, 8-tetrahydrodibenz[c, e]azocines 4b, c and their methoxy and methylenedioxy derivatives 7a-c and 8a-c were prepared by cyclization of O-protected 1-phenyl-2-aminoethanols 6b, c, 9a-c and 10a-c with zerovalent nickel, followed by hydrolysis of the resulting O-protected azocines 4d, e, 7d-f and 8d-f, respectively. The half-tub conformation of the tetrahydroazocine ring of these 8-hydroxydibenz[c, e]azocines and the quasi-equatorial configuration of the 8-hydroxy group were supported by the proton nuclear magnetic resonance spectra.