Efficient synthesis of trisubstituted [1]benzopyrano[4,3-b]pyrrol-4(1H)-one derivatives from 4-hydroxycoumarin
作者:Yuan-Xiu Liao、Pei-Yu Kuo、Ding-Yah Yang
DOI:10.1016/s0040-4039(03)00012-1
日期:2003.2
Various trisubstituted [1]benzopyrano[4,3-b]pyrrol-4(1H)-one derivatives have been synthesized from 4-hydroxycoumarin with a 30–40% yield over six steps. The key step of the synthesis is a base-promoted intramolecular cyclization of enamines 5, followed by dehydration to generate the fused pyrrole ring.
从4-羟基香豆素合成了各种三取代的[1]苯并吡喃并[4,3 - b ]吡咯-4(1 H)-one衍生物,其六步产率为30–40%。合成的关键步骤是烯胺5的碱促进的分子内环化,然后脱水以生成稠合的吡咯环。