[3,3]Sigmatropic ring expansion of cyclic thionocarbonates. 8. highly stereoselective synthesis of (Z- or (E)-double bonds by controlling chairlike-boatlike transition states in the [3,3]sigmatropic rearrangement of 8-membered thionocarbonates
作者:Shinya Harusawa、Hirotaka Osaki、Harumi Fujii、Ryuji Yoneda、Takushi Kurihara
DOI:10.1016/s0040-4020(01)88312-5
日期:1992.1
synthesis of (Z)- or (E)-double bonds in 10-membered thiolcarbonates (3) was successfully conducted by controlling the chairlike-boatlike transition states in the [3,3]sigmatropic rearrangement of 8-membered thionocarbonates (2). The geometry of the product appeared to be highly dependent on the substituent pattern in the allylic system of the substrates (1). The 10-membered thiolcarbonates (3) were readily
通过在8元硫代碳酸酯的[3,3]σ重排中控制椅子状的船状过渡态,成功地进行了10元硫代碳酸酯(3)中(Z)或(E)-双键的高立体选择性合成(2)。产品的几何形状似乎高度依赖于基材(1)的烯丙基体系中的取代基图案。10元硫代碳酸酯(3)易于转化为(Z)-或(E)-烯丙基硫代碳酸酯(11)。(Z)-3j或3i的治疗用锂在液氨中得到高收率的(Z)-三取代或四取代的烯烃(12j和12i)。