Reactions 1‐acetyl‐3‐oxo‐2,3‐dihydroindole with alkyl 2‐cyano‐3‐alkoxypropenoate and alkyl 2‐alkoxycarbonyl‐3‐alkoxy‐propenoate. Synthesis of 9‐acetoxypyrrolo[1,2‐a]indol‐3‐one derivatives

Abstract 1‐Acetyl‐3‐oxo‐2,3‐dihydroindole reacted with methyl 2‐cyano‐3‐methoxypropenoate and ethyl 2‐cyano‐3‐ethoxypropenoate in the presence of sodium hydride, affording compounds 3 (2‐(2‐cyano‐2‐alkoxycarbonyl‐vinyl)‐3‐hydroxyindole). Methyl 2‐methoxycarbonyl‐3‐methoxypropenoate gave compounds 4 or compounds 5 (in the presence of Triton B). Heating compounds 3 or their acetylated derivatives in acetic anhydride at reflux afforded 9‐acetoxy‐(3H)‐pyrrolo[1,2‐a]indol‐3‐one 8.