Radical cyclisation strategies to bridged systems. Regioselective construction of chiral bicyclo [2.2.2] and [3.2.1] octanes via 6-exo trig and 5-exo trig radical cyclisation reactions
作者:A. Srikrishna、P. Hemmalini
DOI:10.1016/s0040-4020(01)85623-4
日期:1992.1
Radical cyclisation reaction of the bromoenones and , obtained from (R)-phenyl carvone , gave a mixture of bicyclo [2.2.2] and [3.2.1] octanones via competitive 6-exo trig and 5-exo trig modes. On the other hand, radical cyclisation reaction of the alcohol furnished the bicyclo[3.2.1]-octanol as the major cyclised product, where as the alcohol furnished the bicyclo[2.2.2]octanol as the major cyclised
所述bromoenones的自由基环化反应和,从(R) -苯基香芹酮获得,得到双环[2.2.2]和混合物[3.2.1] octanones经由竞争性6 -外TRIG和5 -外TRIG模式。另一方面,醇的自由基环化反应提供了主要的环化产物双环[3.2.1]-辛醇,而醇提供了主要的环化产物双环[2.2.2]辛醇。提出了一种基于构象刚度的解释,该构象刚度是由于羟基和甲氧基之间存在分子内氢键而引起的,并通过形成双环[2.2.2]辛烷作为主要的环化产物与相应的乙酸盐和β2来证明。