Crystal Structure of (6S,9S,13R,14S)-7,8-Didehydro-3,7-dimethoxy-17-methylmorphinan-4,6-diol

1 INTRODUCTION (9S,13R,14S)-7,8-Didehydro-3,7-dimethoxy-4-hydroxy-17-methylmorphinan-6-one I is an impor- tant natural product that was used to ease pain, decrease blood pressure and diminish inflammation. In order to study the stereochemistry of the reduction of I with potassium boronhydride, the crystal structure of the title compound II was determined by X-ray diffraction method. 2 EXPERIMENTAL 2. 1 Instrument The melting point was measured on a Yanagimoto MP-500 apparatus…

Crystal Structure of(6S,9S,13R,14S)-7,8-Didehydro-3,7-dimethoxy-17-methylmorphinan-4,6-diol

The title compound (C19H25NO4, Mr = 331.40) was synthesized and its crystal structure was determined by single-crystal X-ray structure analysis. The compound belongs to space group P212121 with a = 7.738(2), b = 10.131(2), c = 21.535(4) ? V = 1688.3(6) 3 and Z = 4. The final R and wR factors are 0.0557 and 0.1489, respectively for 2936 (I > 2s(I)) independent observable reflections. The result shows that the title compound is a tetracyclic alkaloid with four chiral centers, and the absolute configuration of the newly formed one is 6S. The piperidine ring is in chair conformation, while the other two aliphatic rings are in twist boat conformation. The title compound was the mainly isolated reduction product, which means that the hydrogen anion attacks the carbonyl group at the opposite side away from the phenyl group because of its steric effect.