Methyl Group in Isocopalane Derivative Showed an Unusual Negative 1H NMR Chemical Shift  

作　　者：Xiong Xiao Tianqi Chen Fengfeng Zhang Jiagao Cheng Peiying Wu Jiangmeng Ren Bubing Zeng 

机构地区：[1]Shanghai Key Laboratory of New Drug Design,School of Pharmacy,East China University of Science and Technology,Shanghai 200237,China [2]Key Laboratory of Synthetic Chemistry of Natural Substances,Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,Shanghai 200032,China [3]School of Pharmacy,Shanghai University of Traditional Chinese Medicine,Shanghai 201203,China

出　　处：《Chinese Journal of Chemistry》2015年第6期643-645,共3页中国化学（英文版）

基　　金：supported by National Natural Science Foundation of China(No.21302053);Science and Technology Commission of Shanghai Mu-nicipality(No.14DZ1900102);the Fundamental Research Funds for the Central University(No.WY1113007)。

摘　　要：An unusual negative 1H NMR chemical shift of methyl group was discovered in condensation product of isoco-palane diterpenoid with p-toluenesulfonyl hydrazide.2D NMR,computational studies and single-crystal X-ray dif-fraction analysis showed that the C-20 methyl group was shielded.

关 键 词：shielding effect DITERPENOID DIHYDROPYRAZOLE negative chemical shift computational study 

分 类 号：O62[理学—有机化学]