ChemInform Abstract: Intramolecular 1,3-Dipolar Cycloaddition of Alkyl Azidoalkylidenemalonate and 1,3-Dipolar Cycloreversion of the Triazoline Intermediate: Synthesis and Reactions of an N-Sulfonyl-2,4-dihydropyrrolo(3,4-b)indole.

ChemInform Abstract

The dihydropyrroloindole (V) and its ester (VII) are prepared from the indole (I), the key steps being the intramolecular 1,3-dipolar cycloaddition of the azide derived from (III) and the 1,3-dipolar cycloreversion of the triazoline (IV). Diels-Alder reaction of (VII) with the dienophiles (VIII), (X) or (XIII) gives the cycloadducts (IX), (XI), (XII) or (XIV); the latter is converted to the benzocarbazole (XVI).