Preparation and thermal rearrangement of a benzofuran–nitrene adduct

Abstract

Phthalimidonitrene adds to benzo[b]furan to give 1a,6b-dihydro-1-phthalimidobenzofuro[2,3-b]azirine (III). With methanol compound (III) gives the expected products of aziridine ring opening and 19,20-dioxa-9,10-diazapentacyclo[10,7,1,0^1,9,0^2,70^13,18]eicosa-2,4,6,10,13,15,17-heptaen-8-one (VI). The reactions of compound (VI) and its 10,11-dihydro-derivative with sodium methoxide are described.