Regioselectivity on Electroreductive Transannular Reaction of 7-Methylenebicyclo[3.3.1]nonan-3-one
作者:Hiroki Itoh、Ichiro Kato、Kei Unoura、Yasuhisa Senda
DOI:10.1246/bcsj.74.339
日期:2001.2
A competitive transannular reaction occurred to give 7-methyltricyclo[3.3.1.03,7]nonan-3-ol (5) and 1-adamantanol (6) in the non-mediated electroreduction of 7-methylenebicyclo[3.3.1]nonan-3-one (1) in N,N-dimethylformamide. The apparent temperature dependence of the regioselectivity of the reaction may be attributed to the competitive operation of both kinetic and thermodynamic controls in the cyclization
在7-亚甲基双环[3.3.1]壬烷-3的非介导电还原中,发生竞争性跨环反应,得到7-甲基三环[3.3.1.03,7]壬烷-3-醇(5)和1-金刚烷醇(6) -N,N-二甲基甲酰胺中的一 (1)。反应区域选择性的明显温度依赖性可能归因于在羰基自由基阴离子的环化中动力学和热力学控制的竞争性操作。1•-、ΔΔH‡(5-exo - 6-endo)和ΔΔS‡(5-exo - 6-endo)的5-exo-和6-内环化之间的活化参数差异被评估为分别为 -3.1 kcal mol-1 和 -11 cal mol-1 K-1。还进行了半经验 PM3(RHF 和 UHF)计算以阐明反应机理。