Stereoselective synthesis of tetrahydro-2H-[2]benzopyrano[3,4-c]pyrrol-3-ones and related compounds as precursors of serotonin 5-HT2C receptor agonists

Tetrahydro-2H-[2]benzopyrano[3,4-c]pyrrol-3-ones and the related 3a-methyl-2,3,3a,4,5,9b-hexahydro-1H-benzo[e]isoindole analogues were synthesised by an intramolecular Diels–Alder reaction. The observed stereoselectivity was dependent upon the nature of the tethered dienophile as well as the judicious placement of the amide.