作者:Henryk Koroniak、Piotr Karwatka、Tomasz Cytlak
DOI:10.1016/j.tetlet.2004.04.187
日期:2004.7
Phototransformations of derivatives of 5-fluoroalkenyl uracils depend strongly on the fluorinated substituents. 1,3-Dimethyl-5-trifluorovinyluracil when irradiated in water with UV light (λ>300 nm) gives 1,3-dimethyl-(5,6-dihydrourac-6-yl)-difluoroacetic acid as the only product, while the analogous 1,3-dimethyl-5-(E-pentafluoropropenyl)uracil isomerizes to its Z isomer. It is suggested that the first
5-氟链烯基尿嘧啶衍生物的光转化很大程度上取决于氟化取代基。1,3-二甲基-5-三氟乙烯基尿嘧啶在水中被紫外线(λ > 300 nm)照射时,只有1,3-二甲基-(5,6-二氢尿嘧啶-6-基)-二氟乙酸,而类似的1,3-二甲基-5-(E-五氟丙烯基)尿嘧啶异构化为其Z异构体。建议第一个转变是热力学控制的,而第二个转变是动力学控制的,其差异是由于扭转选择性造成的。