题目内容

香豆素与碱反应的特点是:

A. 遇碱后内酯水解开环，加酸后又可环合成内酯环
B. 加碱内酯环水解开环，生成反式邻羟桂皮酸盐
C. 加碱内酯环水解开环，加酸后又可环合成内酯环，但若长时间在碱中加热，生成反式邻羟桂皮酸盐，即使加酸也不能环合
D. 加碱内酯环水解开环，并伴有颜色反应
E. 加碱生成的盐可溶于水

查看答案

搜索结果不匹配？点我反馈

更多问题

Emerson反应为阴性的香豆素是

A. 7,8-二-OH香豆素
B. 8-OCH3-6,7-呋喃香豆素
C. 七叶苷
D. 5,6,7-三-OH香豆素
E. 6-OCH3香豆素

It was John ______ clearn the window.

A. Who
B. whom
C. what
D. which

Was it by train _____ you traveled last summer?

A. which
B. what
C. and
D. that

It was soon after the economic crisis ______ sales of e-business started to grow. (2013,6.A)

A. Why
B. how
C. where
D. that