Crystal structures of 3,3,5,5-tetramethylglutarimide [3,3,5,5-tetramethylazacyclohexane-2,6-dione] (8) and the product of its reaction with phenyllithium, 2-hydroxy-2-phenyl-3,3,5,5-tetramethyl-6-piperidone (9), have been determined by X-ray structural methods [(8), monoclinic, P21/c, a = 7.715 (2), b = 11.136 (2), c = 11.707 (2) Å, \beta = 105.63 (3)°; (9), triclinic, P\overline 1, a = 6.1685 (6), b = 11.1475 (10), c = 11.526 (2) Å, \alpha = 117.100 (10), \beta = 103.390(10), \gamma = 91.288 (7)°]. Molecular structures of three different glutarimides are discussed. Their energy optimal structures were determined with the use of ab initio calculations. The results of crystallographic and theoretical studies show that the conformational changes in glutarimide introduced by substitution with methyl groups resulted in electron-charge distribution changes. These differences in charge distribution are the reason for the observed variation in yields of the reaction of glutarimides with phenyllithium.
通过 X 射线结构方法确定了 3,3,5,5-四甲基戊二酰亚胺[3,3,5,5-四甲基氮杂环己烷-2,6-二酮](8) 及其与苯锂反应的产物 2-羟基-2-苯基-3,3,5,5-四甲基-6-哌啶酮(9) 的晶体结构[(8),单斜,P21/c,a = 7.715 (2), b = 11.136 (2), c = 11.707 (2) Å, \beta = 105.63 (3)°; (9), triclinic, P\overline 1, a = 6.1685 (6), b = 11.1475 (10), c = 11.526 (2) Å, \alpha = 117.100 (10), \beta = 103.390 (10), \gamma = 91.288 (7)°].讨论了三种不同戊二酰亚胺的分子结构。利用 ab initio 计算确定了它们的最佳能量结构。晶体学和理论研究的结果表明,甲基取代戊二酰亚胺引起的构象变化导致了电子电荷分布的变化。这些电荷分布的差异是戊二酰亚胺与苯锂反应的产率发生变化的原因。