Intramolecular Amidofuran Cycloadditions across an Indole π-Bond: An Efficient Approach to the <i>Aspidosperma</i> and <i>Strychnos</i> <i>ABCE</i> Core
作者:Stephen M. Lynch、Scott K. Bur、Albert Padwa
DOI:10.1021/ol027024q
日期:2002.12.1
[reaction: see text] The intramolecular Diels-Alder reaction between an amidofuran moiety tethered onto an indole component was examined as a strategy for the synthesis of Aspidosperma and Strychnos alkaloids. Furanyl carbamate 13 was acylated using the mixed anhydride 16 to provide amidofuran 12 in 68% yield. Further N-acylation of this indole furnished 17 in 88% yield. Cyclization precursors were
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