Pyrolytic cascades: a convenient entry to 5H-pyrrolo[2,1-a]isoindol-5-ones and related heterocyclic systems
Abstract
Flash vacuum pyrolysis (FVP) of 1-(2-methoxycarbonylphenyl)pyrrole 2 at 925 °C (0.001 Torr) gives pyrrolo[2,1-a]isoindol-5-one 1 (79%) by a cascade process involving rate determining 1,5-aryl migration, elimination of methanol and electrocyclisation of the resulting ketene intermediate 3; the related heterocyclic systems 6, 9 and 12 were made by analogous methods.