Rearrangement of spiro[2H‐1‐benzopyran‐2,2′‐[2H]indoles] to pyrrolo[1,2‐a]indole derivatives

Heating of 1′‐(N‐substituted carbamoyl)methylspiro[2H‐1‐benzopyran‐2,2′‐[2H]indoles] with potassium hydroxide in ethanol yields diastereomeric 5a,13‐methano‐6H‐1,3‐benzoxazepino[3,2‐a]indole‐12‐carbox‐amides. Reduction of the latter with sodium borohydride affords 1,2,3,9a‐tetrahydro‐2‐hydroxyaryl‐9H‐pyrrolo[ 1,2‐a] indole‐3 ‐carboxamides.