The octant rule. XVI1. COnformation and circular dichroism of and 2-methylbicyclo[3.1.0]hexan-3-ones, thujone and isothujone
作者:David A. Lightner、Chwang Siek Pak、B.Vincent Crist、Stephen L. Rodgers、John W. Givens
DOI:10.1016/s0040-4020(01)97203-5
日期:1985.1
(lS,5S)-exo-2(R)-Methylbicyclo[3.1.0]hexan-3-one (1) and (lS,5S)-endo-2(S)-methylbicyclo[3.1.0]hexan-3-one (2) were synthesized and their circular dichroism (CD) spectra run. Conformational analysis based on molecular mechanics calculations and Karplus equation analyses of vicinal H¦H NMR coupling constants indicate boat-like sofa conformations for both 1 and 2, with very little ring distortion from
(lS,5S)-exo-2(R)-甲基双环[3.1.0]己-3-(1)和(lS,5S)-endo-2(S)-甲基双环[3.1.0] hexan-3合成一个(2)并运行其圆二色性(CD)光谱。基于分子力学计算的构象分析和邻域HκNMR耦合常数的Karplus方程分析表明,1和2均呈船形沙发构型,而双环[3.1.0] hexan- 3个 分别为1和2的唯一不对称的ψ轴和ψ赤道甲基均是辛烷值。制备和测试天然产物类似物1和2,(-)-3-isothujone(3)和(+)-3-thujone(4)。它们的α-甲基干扰物主导CD n- π ★棉花效应。