题目内容:
6-甲氧基-7-羟基香豆素的H-4信号是
A. 7. 60 (1H, J= 9. 5Hz)
B.
6. 85 (1H, d, J= 9. 5Hz)
C.
6.26 (1H, J = 9. 5Hz)
D.
3. 95 (1H, d, J=9. 5Hz)
E.
6. 91 (1H, d, J =9. 5Hz)
参考答案:
6-甲氧基-7-羟基香豆素的H-4信号是
A. 7. 60 (1H, J= 9. 5Hz)
B.
6. 85 (1H, d, J= 9. 5Hz)
C.
6.26 (1H, J = 9. 5Hz)
D.
3. 95 (1H, d, J=9. 5Hz)
E.
6. 91 (1H, d, J =9. 5Hz)