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

被引:2
|
作者
Xiao, Xiong [1 ]
Chen, Tianqi [1 ]
Zhang, Fengfeng [1 ]
Cheng, Jiagao [1 ]
Wu, Peiying [3 ]
Ren, Jiangmeng [1 ]
Zeng, Bubing [1 ,2 ]
机构
[1] E China Univ Sci & Technol, Shanghai Key Lab New Drug Design, Sch Pharm, Shanghai 200237, Peoples R China
[2] Chinese Acad Sci, Shanghai Inst Organ Chem, Key Lab Synthet Chem Nat Subst, Shanghai 200032, Peoples R China
[3] Shanghai Univ Tradit Chinese Med, Sch Pharm, Shanghai 201203, Peoples R China
基金
中国国家自然科学基金;
关键词
shielding effect; diterpenoid; dihydropyrazole; negative chemical shift; computational study; RING;
D O I
10.1002/cjoc.201500187
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
An unusual negative H-1 NMR chemical shift of methyl group was discovered in condensation product of isocopalane diterpenoid with p-toluenesulfonyl hydrazide. 2D NMR, computational studies and single-crystal X-ray diffraction analysis showed that the C-20 methyl group was shielded.
引用
收藏
页码:643 / 645
页数:3
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