Struktur und Reaktivität von isoanellierten heterocyclischen Systemen mit Anπ- und (4n+2)π-Elektronen, XII [1]. 2-tert-Butyl-4-methyl-2,4-dihydropyrrolo[3,4-b]indole: Tricyclische Hetarene mit isoanellierten Pyrrolringen / Structure and Reactivity of Isoannelated Heterocyclic Systems with 4nπ- and (4n+2)π-Electrons, XII [1] 2-terr-Butyl-4-methyl-2,4-dihydropyrrolo[3,4-b]indoles: Tricyclic Hetarenes with Isoannelated Pyrrole Rings

Abstract

2-tert-Butyl-4-methyl-2,4-dihydropyrrolo[3,4-b]indole (4a) has been prepared via selective reduction of 2-rm-butyl-4-methyl-2,4-dihydropyrrolo[3,4-b]indol-l(2H)-one or -3(2H)-one 5 and 6 with diisobutylaluminiumhydride. The same precursors 5 and 6 can be transformed into 2-tert-butyl-4-methyl-2,4-dihydropyrrolo[3,4-b]indoles (4b) and (4c) bearing a methoxy group in 1- or 3-position via a two step procedure consisting in O-alkylation and CH-deprotonation. NMR Investigations afford an insight into the structure of the stable tricyclic hetarenes.