Chemical and photochemical cyclisations of 1-alkylidene-1,2,3,4-tetrahydro-2-nicotinoyl- and -isonicotinoyl-β-carbolines: a regiospecific synthesis of naucléfine
- 31 December 1976
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 1
- No. 19,p. 2109-2115
- https://doi.org/10.1039/p19770002109
Abstract
1,2,3,4-Tetrahydro-1-methylene-2-nicotinoyl-β-carboline undergoes oxidative photocyclisation to give the indol-[2′,3′ : 3,4]pyrido[1,2-b][2,7]naphthyridinone alkaloid naucléfine and a ring-E isomer. A similar reaction is observed when the β-carboline is treated with acids, but on treatment with nicotinoyl or benzyl halides cyclisation takes place to give one isomer only. Analogous reactions occur with other 2-substituted 1-alkylidene-1,2,3,4-tetrahydro-β-carbolines. The mechanisms of these processes have been investigated and the 1H n.m.r. spectra of both substrates and products have been analysed.This publication has 2 references indexed in Scilit:
- Regiospecific cyclisation of 1,2,3,4-tetrahydro-1-methylene-2-nicotinoyl-β-carbolines: a synthesis of naucléfineJournal of the Chemical Society, Chemical Communications, 1977
- Synthesis of the indolo[2′,3′:3,4]pyrido[1,2-b][2,7]naphthyridinone alkaloid nauclefine and its ring-EisomersJournal of the Chemical Society, Perkin Transactions 1, 1975