A new and efficient method for conjugate addition of trialkylphosphites to 3-acylsubstituted coumarins
作者:Rositca D. Nikolova、Anka G. Bojilova、Nestor A. Rodios
DOI:10.1016/j.tet.2004.08.069
日期:2004.11
A new and efficient conjugate addition of trialkylphosphites to 3-ω-bromoacetylcoumarin 1 catalysed by p-toluenesulfonic acid (TsOH) has been studied. Under the same conditions, an enolphosphate gave the corresponding esters of 3-acetyl-4-phosphono-2-oxochromans in high yields. The use of TsOH in the reaction of 3-acetyl-, 3-benzoyl-, and 3-ethoxycarbonyl coumarins led mainly to 1,4-addition products—the
研究了由对甲苯磺酸(TsOH)催化的亚磷酸三烷基酯向3-ω-溴乙酰香豆素1的新型高效共轭加成反应。在相同条件下,烯醇磷酸酯以高收率得到3-乙酰基-4-膦酰基-2-氧代苯并二氢吡喃的相应酯。TsOH在3-乙酰基,3-苯甲酰基-和3-乙氧基羰基香豆素反应中的使用主要产生了1,4-加成产物-相应的3-酰基-4-二烷基膦酰基-2-氧代苯并二氢吡喃-非常好产量。