ACETOGENIC ISOQUINOLINE ALKALOIDS .23. STRUCTURE OF THE NAPHTHYL ISOQUINOLINE ALKALOID DIONCOPHYLLINE-A .22.

(1R,3R,7S)-7-[1-(4,5-Dimethoxy-2-methyl)naphthyl]-8-hydroxy-1,3-dimethyl-1,2,3,4-tetrahydroisoquinoline, C24H27NO3.CH2Cl2, M(r) = 462.4, orthorhombic, P2(1)2(1)2(1), a = 11.032 (2), b = 12.420 (3), c = 17.080 (8) angstrom, V = 2340.3 angstrom 3, Z = 4, D(x) = 1.31 Mg m-3, lambda(Mo K-alpha = 0.71069 angstrom, mu = 0.3 mm-1, F(000) = 976, T = 290 K, final R = 0.063, for 1617 observed reflections. The structure (constitution and relative configuration) is the same as established recently by spectroscopic, chiroptical, synthetic and degradative methods. A semi-empirical energy minimization calculation yields a structure very close to that of the X-ray analysis.