conformer ap is the most stable. A simple model for the assignment of the absolute configuration from NMR data is presented, and its reliability is corroborated with acids 6-31 of known absolute configuration. In addition to 5, other auxiliary reagents with open (32-38) and cyclic (39-42) structures have also been studied. trans-(+)- and (-)-2-phenyl-1-cyclohexanol (41) was found to be particularly efficient
从其酯与(R)-和(S)-乙基2-羟基-2-(9-
蒽基)
乙酸酯[(R)-和()的酯的1H NMR光谱预测α-手性
羧酸的绝对构型S)-9-AHA,5]。低温NMR实验,MM,半经验和芳族屏蔽效应计算可以识别主要构象异构体,结果表明,在所有研究的酯中,构象异构体ap是最稳定的。给出了一个从NMR数据分配绝对构型的简单模型,其可靠性得到了已知绝对构型的酸6-31的证实。除5外,还研究了其他具有开放(32-38)和环状(39-42)结构的辅助试剂。