作者:Sudipta Pathak、Ashis Kundu、Animesh Pramanik
DOI:10.1016/j.tetlet.2011.07.133
日期:2011.10
A simple and efficient procedure has been developed for the synthesis of substituted pyrrole-fused isocoumarins from easily available ninhydrin. The cyclic hemiaminal dihydroxy-indenopyrroles, the adducts of ninhydrin with enamines of acetylacetone, give pyrrole-fused isocournarins upon heating in acidic medium. The process constitutes an interesting acid-catalyzed rearrangement to eight-membered lactams followed by intramolecular cyclization involving the amino and keto groups. (C) 2011 Elsevier Ltd. All rights reserved.