【摘要】 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Na BH4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1H NMR、13C 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(Corneranti).cis-2,12-二取代环十二酮的Li Al H4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.更多还原

【Abstract】 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 / cyclohexylcyclododecanones 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 Na BH4 reduction of 2-substituted cyclodode-canones,ring-opening of cyclododecene oxide,Mitsunobu reaction of cis-2-phenyl cyclododecanol and hydrolysis,their preferred conformation were analyzed on the basis of1 H NMR,13 C NMR,X-ray diffraction 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 sideexo 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 cornersyn,three groups are cis-cis relationships.更多还原