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单晶X射线衍射分析表明,几个新的α-单取代环十二酮与氨衍生物羟胺发生反应得到三种母体构象分别为[3333]和[2334],而取代基为边外向或角反向的α-单取代环十二酮肟.利用底物的“角位羰基参与反应”原理,“记忆效应”及进攻试剂与底物是否形成氢键解释了这一实验结果.通常取代基体积较大以及α-取代基与羰基形成分子内氢键情况下,试剂从空间障碍小以及远离氢键的一面进攻羰基生成α-角反取代环十二酮肟;当试剂与底物的取代基之间能够形成强的分子间氢键时,生成α-边外取代环十二酮肟;当试剂与底物的取代基之间只能形成弱的分子间氢键以及底物的取代基较小时,试剂从两面进攻羰基同时生成α-角反取代环十二酮肟和α-边外取代环十二酮肟.
Single crystal X-ray diffraction analysis showed that several new α-monosubstituted cyclododecanone reacted with ammonia derivative hydroxylamine to give three kinds of parental conformations [3333] and [2334] Reverse α-monosubstituted cyclododecanone oxime This experimental result is explained by the fact that the substrate’s “angular carbonyl-participating reaction” principle, the “memory effect” and the attacking agent’s hydrogen bond to the substrate In general, when the substituent is bulky and the intramolecular hydrogen bond between the α-substituent and the carbonyl group causes the reagent to attack the carbonyl group from the small space obstacle and away from the hydrogen bond to generate α-angle anti-substituted cyclododecanone oxime, Substitution of the substrate to form a strong intermolecular hydrogen bond, the generation of α-side outside the ring instead of cyclododecanone oxime; when the reagent and substrate substituents can only form a weak intermolecular hydrogen bond and the bottom When the substituent of the substance is small, the reagent attacks the carbonyl group from both sides and simultaneously generates α-angle anti-substituted cyclododecanone oxime and α-side substituted cyclododecanone oxime.