四氢β—咔啉类化合物的~1H NMR及立体化学研究

THE STUDY ON ~1H NMR AND STEREOCHEMISTRY OF TETRAHYDRO-β-CARBOLINES

本文提供了三类(六个)代表性四氢β-咔啉化合物的2D-NMR的同核二维相关谱(cosy)和同核NOE谱(NOESY)。根据实验测得的分子中有关基团间显示的NOE关系,指定了所有化合物的构型。借助分子模型,讨论了它们的构象。

L-Tryptophanc methyl ester reacts with corresponding monoacetal of malonaldchydc under Pictct - Spenglcr conditions followed by Michael additions of methyl vinyl ketone to give diastereoisomcrs of tetrahydro -??-carbolines l_(a.) _b, 2_(a,b) and 3_(a,b) . Their COSY and NOESY 2D-NMR spectroscopy were studied here. It was shown that in 1_a, 2_a, and 3_a, there were NOE relationships between 3 -H and 3 '-H, in l_b , 2_b , and 3_b however there were NOE relationships between OCH_3 and CO_2CH_3 (for l_b and 2_b) or between 5 '-CH_3 and CO_2CH_3 (for 3_b). Based on the results of NOE and the help of Dreiding Stereomodels their conformations were discussed.