作者:V.K. Ahluwalia、K.K. Arora
DOI:10.1016/s0040-4020(01)92463-9
日期:1981.1
A novel method of nuclear isoprenylation leading to the exclusive formation of 2,2-dimethylchromans has been achieved by the direct condensation of polyhydroxyacetophenones with isoprene in presence of phosphoric acid. Acetylchromans, thus obtained, are dehydrogenated with DDQ to given corresponding 2,2-dimethylchromenes. Using this method, synthesis of number of naturally occurring chromenes, viz
通过在磷酸的存在下聚羟基苯乙酮与异戊二烯的直接缩合,已经实现了导致异戊二烯仅形成2,2-二甲基苯并二氢吡喃的新型核异戊烯化方法。将如此获得的乙酰基苯并二氢吡喃酮用DDQ脱氢,得到相应的2,2-二甲基苯并二苯甲基。使用这种方法,可以合成许多天然存在的色烯。ripariochromene A(6),eupatoriochromene(10),encecalin(11),isoevodionol(16),evodionol(17)和甲基evodionol(18)已受影响。