Authors: De Souza, M.V.N.; Yan, Z. ; Dodd, R. H.
Source: Heterocycles, v. 64, p. 261, 2004.
Publisher: The Japan Institute of Heterocyclic Chemistry Publications
Abstract
4-Allyloxy- and 4-prop-2-ynyloxy-3-iodopicolinic acid derivatives, obtained by reaction of 4-chloro-2-iodopicolinanilides (11,14) with the sodium salts of allyl alcohol and propargyl alcohol, respectively, were subjected to tri-n-butyltin hydride/AIBN free radical cyclization conditions. While the propargylic compound (15) did not cyclize, the allylic compounds (8, 28) cyclized in the presence of diphenyl diselenide, TEMPO or oxygen as radical trapping agents to give the corresponding 2,3-dihydrofuro[3,2-c]pyridine-4-carboxylic acid derivatives substituted at C-3 by a phenylselenylmethyl (20), 2,2,6,6-tetramethylpiperidin-1-yloxymethyl (22) or hydroxymethyl group (29), respectively. The latter was oxidized to the 3-carboxylic acid using ruthenium chloride /sodium periodate and the C-4 benzyl ester was hydrogenolyzed to afford the title compound (5), a conformationally constrained analogue of the subtype selective NMDA receptor agonist, homoquinolinic acid.Keywords: None Document Type: Research Article DOI: http://dx.doi.org/10.3987/COM-04-S(P)22 Publication date: 3 de Setembro de 2004
