Syntheses of 6-acylcoumarins via highly regioselective fries rearrangements. Total syntheses of the linear acylated coumarins geijerin and dehydrogeijerin.
作者:Nicholas Cairns、Laurence M. Harwood、David P. Astles
DOI:10.1016/s0040-4020(01)90370-9
日期:1992.9
in general and efficient syntheses of 6-acylcoumarins. Under standard Fries rearrangement conditions (7) undergo highly regioselective para-migration with aluminiumchloride in nitromethane. The resulting C-acylated products (8) are converted into 6-acyl-7-methoxycoumarins (4). The scope and limitations of the rearrangement and the application to the total syntheses of the natural linear acylcoumarins