Synthesis and Conformation Analysis of cis-1,2-Disubstituted Cyclododecanes  

作　　者：韩翔宇 王明安 李太公 梁晓梅 董燕红 陈馥衡 王道全 

机构地区：[1]Department of Applied Chemistry, China Agricultural University

出　　处：《Chinese Journal of Structural Chemistry》2007年第6期625-631,共7页结构化学（英文）

基　　金：Presented in part at the Third National Symposium of the Chinese Chemical Society on Organic Chemistry, Lanzhou, China, August, 2004 (for abstract, see Chin. J. Org. Chem., 2004, Suppl. 365);This project was supported by the National Natural Science Foundation of China (No. 20072053)

摘　　要：cis-1,2-Disubstituted cyclododecanes 2 were synthesized by sodium borohydride reduction of 2-monosubstituted cyclododecanones and their structures were confirmed by 1HNMR, ^13C NMR and elemental analysis. The higher cis-selectivity of NaBH4 reduction of 2- monosubstituted cyclododecanones was rationalized by the mode of ＂corner position carbonyl participation＂. Crystal data for 2c： Mr = 263.21, monoclinic, space group P21/c, a = 1.11140（7）, b = 2.62590（17）, c = 0.91360（6） nm, β= 106.1840（10）°, V = 2.5606（3） nm^3, Dc = 1.366 g/cm^3, Z = 8, F（000） = 1104, μ（MoKα= 3.182 mm^-1, S = 0.837, the final R = 0.0460 and wR = 0.1033. Crystal X-ray diffraction analysis for 2c showed that its ring skeleton adopts [3333] conformation, in which the OH group presents at the side-exo position and the other one at the corner carbon. The 1H NMR data of 2 showed that 1-corner-R-2-side-exo-OH [3333] and 1-corner-OH-2-side-exo-R [3333] conformations coexist in dynamic equilibrium in the solution, but only the former presents in the crystal.cis-1,2-Disubstituted cyclododecanes 2 were synthesized by sodium borohydride reduction of 2-monosubstituted cyclododecanones and their structures were confirmed by 1HNMR, ^13C NMR and elemental analysis. The higher cis-selectivity of NaBH4 reduction of 2- monosubstituted cyclododecanones was rationalized by the mode of ＂corner position carbonyl participation＂. Crystal data for 2c： Mr = 263.21, monoclinic, space group P21/c, a = 1.11140（7）, b = 2.62590（17）, c = 0.91360（6） nm, β= 106.1840（10）°, V = 2.5606（3） nm^3, Dc = 1.366 g/cm^3, Z = 8, F（000） = 1104, μ（MoKα= 3.182 mm^-1, S = 0.837, the final R = 0.0460 and wR = 0.1033. Crystal X-ray diffraction analysis for 2c showed that its ring skeleton adopts [3333] conformation, in which the OH group presents at the side-exo position and the other one at the corner carbon. The 1H NMR data of 2 showed that 1-corner-R-2-side-exo-OH [3333] and 1-corner-OH-2-side-exo-R [3333] conformations coexist in dynamic equilibrium in the solution, but only the former presents in the crystal.

关 键 词：reduction 2-monosubstituted cyclododecanone cis-1 2-substituted cyclododeca- ne corner position carbonyl participation conformation analysis 

分 类 号：O623.11[理学—有机化学]