摘要：
To confirm the cis-selectivity on the reduction of 2-substituted cyclododecanone and analyze the preferred conformation of trans-1,2-disubstituted cyclododecanes, the reduction of 2-phenyl/cyclohexylcy-clododecanones were carried out at the different reductive reagents and temperatures. Based on these results, a series of trans-1, 2-disub- stituted cyclododecanes was prepared via NaBH4 reduction of 2-substituted cy-clodode- canones, ring-opening of cyclododecene oxide, Mitsunobu reaction of cis-2-phenyl cyclododecanol and hydrolysis, their preferred conformation were analyzed on the basis of 1 H NMR, 13 C NMR, X-ray diffrac-tion and quantum chemistry calculation. The results showed that the preferred conformations of trans-1,2-disubstituted cyclododecanes were [3333] square conformation, in which the one group presents at the side-exo position and the other one at the corner-anti. The X-ray diffraction structures of the reductive products of cis-2 ,12-disubstituted cyclododecanones showed that 1 ,2 ,3-trisubstituted cyclodode- canes still take [ 3333 ] square conformation, in which the two groups present at the side-exo positions and the hydroxy at the corner-syn, three groups are cis-cis relationships.%通过研究2-苯基/环己基环十二酮在不同还原剂和温度下的还原反应证实了2-取代环十二酮的还原反应具有cis-选择性。在此基础上,通过2-取代环十二酮的NaBH4还原反应、1,2-环氧环十二烷的开环反应及cis-2-苯基环十二醇的Mitsunobu反应和水解反应制备了一系列trans-1,2-二取代环十二烷；采用1 H NMR、13 C NMR、X射线衍射和量子化学计算等方法对其优势构象进行了分析。结果表明, trans-1,2-二取代环十二烷的优势构象为[3333]方形构象,1个取代基位于边碳外向位(Side-exo),另1个位于角碳反向位(Corner-anti)。 cis-2,12-二取代环十二酮的LiAlH4还原产物的X射线衍射分析结果表明,生成的1,2,3-三取代环十二烷保持了环十二烷的[3333]方形构象,2个取代基位于边碳外向位,羟基位于角碳顺向位(Corner-syn),取代基呈现出cis-cis关系。
