Synthesis of 2,3‐dihydro‐3‐hydroxy‐2‐(pyrrol‐1‐ylmethyl)‐1<i>H</i>‐isoindol‐1‐one. An intermediate for the synthesis of tetracyclic systems

Abstract

Abstract N ‐Chloromethylphthalimide 1 and the potassium salt of pyrrole gave N ‐(pyrrol‐1‐ylmethyl)pbthalimide 2 . Reduction of 2 led to the hydroxyisoindolone 3 . This hydroxylactam cyclized under acidic conditions to lead to a pyrroloimidazoloisoindolone 4 via an acyliminium ion. Transformation of 3 with acetic acid derivatives provided 5, 7 and 9 which gave by intramolecular cyclization, tetracyclic compounds 6, 10 and 11 .