A New Strategy toward Indole Alkaloids Involving an Intramolecular Cycloaddition/Rearrangement Cascade
作者:Albert Padwa、Michael A. Brodney、Stephen M. Lynch、Paitoon Rashatasakhon、Qiu Wang、Hongjun Zhang
DOI:10.1021/jo049808i
日期:2004.5.1
The intramolecular Diels−Alder reaction between an amidofuran moiety tethered onto an indole component was examined as a strategy for the synthesis of Aspidosperma alkaloids. Furanyl carbamate 23 was acylated using the mixed anhydride 26 to provide amidofuran 22 in 68% yield. Further N-acylation of this indole furnished 27 in 88% yield. Cyclization precursors were prepared by removing the carbamate