The conversion of dihydrothebainone to codeine or thebaine has been achieved in high yield. Bromination and dehydrobromination constructs the 4,5-oxide bridge to give 1-bromo- and 1,7-dibromodihydrocodeinone which yield dihydrocodeinone practically quantitatively after catalytic debromination. Ketalization and acid-catalyzed elimination of methanol give excellent yields of delta6-dihydrothebaine to which is added methyl hypobromite using N-bromoacetamide in methanol. The action of potassium tert-butoxide in Me2SO on the resulting 7-bromodihydrocodeinone dimethyl ketal gives codeinone dimethyl ketal selectivity at 60 degrees while at 120 degrees thebaine is the exclusive product. Hydrolysis to codeinone and borohydride reduction give codeine in 70% overall yield. The bromo intermediates in the formation of the 4,5-oxide bridge have been examined. 1,5beta, 7alpha-Tribromodihydrothebainone has been identified as the main product in the tribromination of dihydrothebainone.

中文翻译：

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从二氢茶黄酮实际合成可待因。

高产率地实现了二氢蒂巴酮向可待因或蒂巴因的转化。溴化和脱氢溴化作用可构建4,5-氧化桥，得到1-溴-和1,7-二溴二氢可待因酮，在催化脱溴后实际上可定量地产生二氢可待因酮。缩酮化和酸催化消除甲醇可得到出色的δ6-二氢蒂巴因产量，并使用甲醇中的N-溴乙酰胺向其中添加了次氯酸甲酯。叔丁醇钾在Me2SO中对所得的7-溴二氢可待因酮二甲基缩酮的作用在60度时可可酮二甲基缩酮的选择性，而在120度时，蒂巴因是唯一的产物。水解成可待因酮和硼氢化物还原得到可待因，总产率为70％。已经检查了在4，5-氧化物桥的形成中的溴中间体。1，