Photochemical formation of chrysanthemic acid and cyclopropylacrylic acid derivatives
作者:P. Baeckström
DOI:10.1016/0040-4020(78)80252-x
日期:1978.1
Photochemical transformations of methyl E- and Z - 4,4,6 - trimethyl - 2,5 - dienoate (5a) and of the corresponding acids (5b) have been investigated. In contrast to similar pure hydrocarbon di-π-methanes, these aliphatic α,β-unsaturated car☐ylic acid derivatives react from both the singlet and the triplet excited states and form different types of vinylcyclopropanes depending on multiplicity. When
已经研究了甲基E-和Z-4,4,6-三甲基-2,5-二烯酸酯(5a)和相应酸(5b)的光化学转化。与类似的纯烃二-π-甲烷相反,这些脂肪族α,β-不饱和的汽车丙烯酸衍生物从单重态和三重态激发态起反应,并根据多重性形成不同类型的乙烯基环丙烷。当在丙酮中照射时,5aE和5aZ均产生甲基E-3(2,2,3,3-四甲基环丙基)prop-2-烯酸酯(8aE)。对于相应的酸观察到相同的结果。直接辐照5aE而不是5aZ可以很容易地得到E-菊苣酸甲酯(4aE)。只有单重态激发的5Z通过内部氢提取反应生成环丙基乙酸加成衍生物(7)。描述了独立合成7和8的程序。