α-单取代环十二酮构象间相互转换的理论研究  

Theoretical Study on the Interconversion of α-Monosubstituted Cyclododecanone Conformations

作　　者：路慧哲[1] 王明安[1] 王道全[1] 

机构地区：[1]中国农业大学应用化学系,北京100094

出　　处：《高等学校化学学报》2004年第1期120-123,共4页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :2 0 0 72 0 53 )资助

摘　　要：在 CV FF力场下 ,DMSO氛围中 ,通过分子动力学常温模拟研究α-单取代环十二酮的构象 ,常温优势构象为α-边外取代 [3333] - 2 -酮 ,环骨架为 [3333] ,羰基位于 C2位置 ,取代基位于α-边外向位 .动态分析带有不同取代基的 α角顺取代和 α-边外取代 [3333] - 2 -酮构象的相互转化的结果表明 ,它们的转换路径基本一致 ,转换能垒随着取代基体积的增大而升高 .氯和溴取代环十二酮转换过程中最高能垒分别为 4 3.9和4 4.3k J/mol,相应的构象为 α-边外取代 [312 33] - 2 -酮 ;甲基、乙基和叔丁基取代环十二酮最高转换能垒达53.9k J/m ol,相应的构象为 α-边外取代 [312 33] - 2 -酮 ;存在活泼质子的氨基和羟基环十二酮转换能垒中最高能量构象为 α-边外取代 [3132 3] - 1-酮 ;苯硫基和苄基取代环十二酮除出现 α-边外取代 [3333] - 2 -酮构象外 ,转换过程中还出现了较 α-角顺取代 [3333] - 2 -酮构象更稳定的 α-边外取代 [4 2 33] - 3-酮构象 .Under the CVFF force field and in DMSO, the conformations of α-monosubstituted cyclododecanones were studied by molecular dynamics at room temperature. The results show that the ring skeleton of the preferred conformation is [3333], with the carbonyl group being present in the C2 position, which is consistent with the experimental results. The interconversion between α-corner-syn-[3333]-2-one and α-side-exo-[3333]-2-one was analyzed by using dynamics mimesis method. The calculated results show that their interconversion paths are consistent basically, the preferred conformation is α-side-exo-[3333]-2-one and the interconversion energy barrier is increased along with the increase of the volume augmentation of the substituent groups. For α-chloro- and bromo-cyclododecanones, the maximum barriers are 43.9 and 44.3 kJ/mol, respectively, and the corresponding conformation is α-side-exo-[31233]-2-one. For α-alkylcyclododecanones, the maximum barrier is as high as 53.9 kJ/mol, and the corresponding conformation is α-side-exo-[31233]-2-one. While α-amino- and hydroxy-cyclododecacones, the conformation of the maximum energy is α-side-exo-[31323]-1-one, and α-phenylthio- and benzyl-cyclododecanones, apart from {α-side-}exo-[3333]-2-one conformation, the another stable conformation is α-side-exo-[4233]-3-one instead of α-corner-syn-[3333]-2-one.

关 键 词：α-单取代环十二酮 构象 转换曲线 分子动力学模型 分子结构 

分 类 号：O624.42[理学—有机化学] O621.13[理学—化学]