The synthesis and stereochemistry of derivatives of 1,2,3,4,6,11,12,13,14,14a-decahydropyrido[1,2-b][2]benzazonine. Crystal structure of 1,2,3,4,4a,5,6,7,7a,12-decahydro-7-phenylisoindolo[1,2-d]quinolizin-13-ium tosylate

Abstract

Catalytic reduction of the pyridine ring of 2-phenyl-2-[2-(2-pyridyl)ethyl]indan-1,3-dione gives, by ring opening of the initially produced carbinolamine, 12-phenyl-1,2,3,4,12,13,14,14a-octahydropyrido[1,2-b]benzazonine-6,1 1-dione. This adopts a piperidine ring conformation with an axial alkyl residue, and the low-temperature ¹³C n.m.r. spectrum shows the presence of two rotamers about the N-aroyl moiety. The derived 11-hydroxy-1 2-phenyldecahydropyrido[1,2-b][2]benzazonine prefers the trans-fused ring conformation and attempts to form the toluene-p-sulphonate of this gave rel-(4aR,7R,7aR,13R)-1,2,3,4,4a,5,6,7,7a,12-decahydro-7-phenylisoindolo[1,2-d]quinolizin-13-ium tosylate. An X-ray structural analysis of the tosylate was performed.