Synthesis of 1<I>H</I>-Pyrrolo [1, 2-a] indole Derivatives. II. Synthesis of 7-Nitro-2, 3, 9, 9a-tetrahydro-1<I>H</I>-pyrrolo [1, 2-a] indoles

Abstract

In connection with synthesis of the ring system of mitomycins, 1H-pyrrolo [1, 2-a] indoles (HI to VI) were synthesized. Indole (XVIII) was synthesized by the reaction of aminodiester (XVII) and 2-chloro-5-nitrobenzaldehyde in one step. Dieckmann reaction of XVIII afforded pyrroloindole (III). By the carbene cyclization reaction, tosylhydrazone (XX) of aldehyde (XIX) gave the compound IV in poor yield, and tosylhydrazones (XXV and XXX) of ketones (XXIV and XXVIII) afforded the desired pyrroloindoles (V and VI) in good yield, respectively.