par Rouchaud, Anne ;Braekman, Jean Claude
Référence European Journal of Organic Chemistry, 12, page (2346-2353)
Publication Publié, 2011
Article révisé par les pairs
Résumé : When diethyl malonate was added to a solution of Δ 1- piperideine, generated in situ by oxidative desamination and decarboxylation of L-lysine by N-bromosuccinimide (NBS), formation of the unexpected tricyclic compound 6 (4-diethylmalonyl-octahydro-4H-pyrrolo[1,2-c]pyrido[1′, 2′-a]imidazole)was observed. The structure of 6 was deduced from analysis of its spectroscopic data and was confirmed both by chemical degradation and by total synthesis. We proved that 3-bromo-1-piperideine was implicated in its formation. Moreover, based on this feature, a new and efficient synthesis of 6 was developed. The elaborated pathway was adapted to access derivatives related to 6 that differed in their C-4 substituent. A new and efficient synthesis of derivatives of the tricyclic heterocycle A from lysine is described. A mechanism involving 3-halopiperideines as intermediates and based on a ring contraction followed by Michael reaction is proposed and tested. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.