Structure Determination of Brominated Morphinan-6-ones by13C-NMR. Spectroscopy: A novel closure of the oxygen bridge using 4-acetoxymorphinan-6-ones
作者:Arnold Brossi、Fu-Lian Hsu、Kenner C. Rice、Maria D. Rozwadowska、Helmut Schmidhammer、Charles D. Hufford、Chian Chian Chiang、Isabella L. Karle
DOI:10.1002/hlca.19810640545
日期:1981.7.22
Bromination of (−)-4-hydroxy-N-methylmorphinan-6-one (3), prepared from natural morphine, with 1 mol of bromine in acetic acid, afforded the 1-bromo ketone 5. The structure of 5 was assigned by 13C-NMR.spectroscopy, and confirmed by X-ray diffraction analysis of its hydrobromide salt. It is suggested that monobromination of synthetic (±)-2,4-dihydroxy-N-formylmorphinan-6-one (7) takes in principle
由天然吗啡制备的(-)-4-羟基-N-甲基吗啡喃6-1(3)与1摩尔的溴在乙酸中的溴化,得到1-溴代酮5。5的结构通过13 C-NMR光谱确定,并通过其氢溴酸盐的X射线衍射分析确认。建议合成(±)-2,4-二羟基-N-甲酰基吗啡喃-6-一(7)的单溴化原理相似,尽管一级反应产物9的13 C-NMR谱不能由于在常用溶剂中不溶而被测量。(-)-4-乙酰氧基-N的单溴化天然系列的-甲酰基吗啡喃-6-(12)和合成系列的(±)-2,4-二乙酰氧基-N-甲酰基吗啡喃-6-one(8),然后用钾处理单溴代酮在甲醇中的碳酸根导致O-桥的闭合,并且在酸水解后分别提供相应的4,5-环氧-吗啡喃-6-(-)- 16和(±)-17。闭环反应的这种变化代表了一种新颖且方便的方法,该方法将4-羟基吗啡喃-6-酮转化为其相应的4,5-环氧吗啡喃-6-酮,而无需涉及芳族溴化且仅含1摩尔溴。