Barton esters were prepared starting from different carboxylic acids loaded on a Wang resin. Light induced fragmentation occurred giving a radical that reacted with CBrCl3 to give the corresponding bromides, whereas conjugate addition to electron-poor alkenes proved to be less synthetically useful. The bromides so formed were further functionalised on the resin with different nucleophiles.
从装载在Wang
树脂上的不同
羧酸开始制备Barton酯。发生光诱导的断裂,产生一个自由基,该自由基与CBrCl 3反应,得到相应的
溴化物,而共轭加成到电子贫乏的烯烃上,则在合成上没有多大用处。如此形成的
溴化物用不同的亲核试剂在
树脂上进一步官能化。