The o-hydroxyformylcoumarin 5b, easily prepared from compound 1, is further transformed to the title coumarin derivatives 7, 10, 19a-c via its initial Wittig olefination with ylides 2b, 8, 18a-c respectively. Coumarins 16a, b were also formed by treatment of 5b with compounds 15a, b. The preparation of the interesting furocoumarin derivatives 11, 14, 20b, c as well as of compound 13 is also described
容易从化合物1制备的邻羟基甲酰基
香豆素5b进一步通过分别与酰化物2b, 8、18a -c的初始Wittig烯化进一步转化为标题
香豆素衍
生物7、10、19a -c。
香豆素16a,b也通过用化合物15a,b处理5b而形成。还描述了有趣的
呋喃香豆素衍
生物11、14、20b,c以及化合物13的制备。