BROMINATIVE DECARBOXYLATION OF BICYCLO[2.2.2]OCTANE-1-CARBOXYLIC ACID IN HALOGENATED SOLVENTS
BROMINATIVE DECARBOXYLATION OF BICYCLO[2.2.2]OCTANE-1-CARBOXYLIC ACID IN HALOGENATED SOLVENTS
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DOI：
10.1021/jo01037a062
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发表时间：
1963-01-01
影响因子：
3.6
通讯作者：
HOLTZ, HD
中科院分区：
文献类型：
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作者：
BAKER, FW;STOCK, LM;HOLTZ, HD
双环[2.2. 2]辛烷-1-羧酸在氧化汞存在下在四氯化碳中产生可观量的1-氯-和1-溴双环[2.2. 2 [辛烷。即使在溴三氯甲烷中，也存在一些1-氯双环[2.2. 2]形成辛烷。这些结果很容易解释的自由基机制的基础上。中间体1-双环[2.2. 2 [辛基]自由基显然具有足够的反应性，可从溴三氯甲烷中提取氯而不是溴。将酸和氧化汞的混合物加入到过量的溴三氯甲烷中，得到所需的1-溴-双环[2.2. 2 [辛烷]，不受氯化物污染。在1，2-二溴乙烷中反应可得到纯溴化物。酸和氧化物与碘在四氯化碳中的反应产生1-双环[2.2. 2]辛基双环[2.2. 2]辛烷-1-羧酸酯和1-氯双环[2.2. Hunsdiecker反应，即羧酸的银盐在分子卤素存在下的脱羧反应，经常是引入卤素的有价值的方法。[3]最近，Criminal和Firth证明，氧化汞与羧酸一起使用具有相当大的优势，避免了完全无水条件的必要性。4我们尝试将该反应用于合成1-溴双环[2.2. 2]辛烷值然而，采用常规条件，即，
The brominative decarboxylation of bicyclo [2.2. 2] octane-l-carboxylic acid in the presence of mercuric oxide in carbon tetrachloride yields appreciable quantities of both 1-chloro-and 1-bromobicyclo [2.2. 2 [octane. Even in bromotrichloromethane some 1-chlorobicyclo [2.2. 2] octane is formed. These results are readily interpreted on the basis of a free radical mechanism. Theintermediate 1-bicyclo [2.2. 2 [octyl free radical is apparently sufficiently reactive to abstract chlorine rather than bromine from bromotrichloromethane. The addition of a mixture of acidand mercuric oxide to excess bromine in bromotrichloromethane provides the desired 1-bromo-bicyclo [2.2. 2 [octane free ofcontamination by the chloride. It was also found that the pure bromide was ob-tained by reaction in 1, 2-dibromoethane. The reaction of the acid and oxide with iodine in carbon tetrachloride yields 1-bicyclo [2.2. 2] octyl bicyclo [2.2. 2] octane-l-carboxylate and 1-chlorobicyclo [2.2. 2 [octane.The Hunsdiecker reaction, the decarboxylation of the silver salt of a carboxylic acid in the presence of molecular halogen, frequently is a valuable method for the introduction ofhalogens. 3 Recently, Cristol and Firth demonstrated that the use of mercuric oxide with the carboxylic acid possessed considerable ad-vantage obviating the necessity for fully anhydrous conditions. 4 We attempted to apply this reaction for the synthesis of 1-bromobicyclo [2.2. 2] octane. How-ever, the adoption of conventional conditions, ie,