A NOVEL MECHANISM FOR THE OXIDATION OF <i>ERYTHRO</i>-SERIES PENTOSES AND HEXOSES BY <i>N</i>-ARYLBROMOSULPHONAMIDES IN ALKALINE MEDIUM
作者:V. Shashikala、K. S. Rangappa
DOI:10.1081/car-120004334
日期:2002.6.27
oxidation of d-mannose, d-glucose, d-fructose, l-arabinose and d-ribose by bromamine-T (sodium N-bromo-p-toluenesulphonamide or BAT) and bromamine-B (sodium N-bromobenzenesulphonamide or BAB) in alkaline medium were investigated at 30°C. The rate of the reaction was first order both with respect to the oxidant and the sugar and second order with respect to [HO−]. The addition of the reaction product,
溴胺-T(N-溴-对甲苯磺酰胺钠或BAT)和溴胺-B(N-溴苯磺酰胺钠)氧化d-甘露糖,d-葡萄糖,d-果糖,l-阿拉伯糖和d-核糖的动力学研究在碱性介质中于30°C进行了研究。反应速率相对于氧化剂和糖都是一阶的,而相对于[HO-]而言是二阶的。反应产物,对甲苯磺酰胺(PTS)或苯磺酰胺(BSA)的添加以及介质离子强度的变化对速率没有影响。该速率随介质介电常数的降低而降低,并计算出dAB值(活化复合物的大小)。质子清单研究是在H2O-D2O混合物中进行的。反应的激活参数是从阿伦尼乌斯图计算的。产物的HPLC和GLC-MS分析表明,糖被氧化成由阿拉伯酸,核糖酸,赤藓酸和甘油酸组成的醛糖酸的混合物。已经提出了与观察到的结果一致的一般机制。