Reactions of allyloxy(methoxy)carbene in solution. Carbene rearrangement and Claisen rearrangement of the carbene dimer
作者:Damian Plazuk、John Warkentin、Nick Henry Werstiuk
DOI:10.1016/j.tet.2005.04.024
日期:2005.6
Allyloxy(methoxy)carbene, with and without deuterium in the α-position of the allyloxy group, was generated in benzene at 50 and at 110 °C. At the higher temperature, the carbene fragmented to allyl and methoxycarbonyl radicals that subsequently coupled. At the lower temperature, most of the carbene dimerised. The structure of the major product and the distribution of deuterium indicated that the dimer
在50℃和110℃下在苯中生成烯丙氧基(甲氧基)卡宾,烯丙基氧基的α位带有或不带有氘。在较高的温度下,卡宾断裂成烯丙基和甲氧羰基自由基,这些自由基随后偶联。在较低的温度下,大部分卡宾二聚。主要产物的结构和氘的分布表明,二聚体在50°C下进行了Claisen重排,生成2-烯丙氧基-2-甲氧基-4-戊烯酸甲酯。计算结果支持二聚体的容易重排,该计算结果将势垒置于约18kcal mol -1。