TY - JOUR
T1 - Cyclization of 1,5-dinitrile systems with hydrogen halides
T2 - A search for the undetected key tautomer
AU - Teixidó, Jordi
AU - Borrell, José I.
AU - Serra, Blanca
AU - Colominas, Carles
AU - Batllori, Xavier
AU - Piniella, Joan F.
AU - Alvarez-Larena, Angel
N1 - Funding Information:
Support of this work by a grant from the ('omisi6n Intermmisterial de Ciencia y Tecnologia and the Comi,~wi6 lnterdepartamental de Recerca i hmovaci6 Tecnoh)gica within the Programa de Quimica Fma (QFN93-4420). Two of us (B. S. and C. C.) would like to thank Fundaci6n Juan Salanyer and IBM EL~paha respectively for a grant. References and Notes 1. Johnson, F.; Madrofiero, R. In Adv. Heterocycl. Chem.; Katritzky, A R. Ed; Academic Press; New York, 1966; Vol. 6, pp. 95-146. 2. Yanagida, S.; Okahara, M.; Komori, S. In Adv. Org. (;hem.; BOhme, H; Viehe, H. G. Eds; John Wiley and Sons, Inc; New York, 1979; Vol. 9, part 2, pp. 527-571 3. Allestein, E.; Fuchs, R. Chem. Ber. 1968, 101, 1244-1249. 4. Kristinsson, H. J. Chem. Soc., (?hem. Commun. 1974, 350. 5. Perez, M. A.; Soto, J. L.; Guzman, F.; Alcal& H J. Chem. Soc. Perkin Trans. 1 1985, 87-91.
PY - 1997/3/24
Y1 - 1997/3/24
N2 - The 13C NMR spectra of the pyridones 7a-d recorded in DMSO-d6 show three groups of signals which correspond to the two diastereomers of the 7-exo tautomer and the 7-endo tautomer. The X-ray powder analysis and the molecular structures of 7a-c clearly prove that these compounds, and probably 7d, are present in the solid state as a single diastereomer of the 7-exo tautomer which, on being dissolved, establishes an equilibrium with the other diastereomer through the 7-endo tautomer. This later had been proposed as a hey intermediate in the cyclization of the 1,5-dinitrile system present in 7a-d but was not previously detected.
AB - The 13C NMR spectra of the pyridones 7a-d recorded in DMSO-d6 show three groups of signals which correspond to the two diastereomers of the 7-exo tautomer and the 7-endo tautomer. The X-ray powder analysis and the molecular structures of 7a-c clearly prove that these compounds, and probably 7d, are present in the solid state as a single diastereomer of the 7-exo tautomer which, on being dissolved, establishes an equilibrium with the other diastereomer through the 7-endo tautomer. This later had been proposed as a hey intermediate in the cyclization of the 1,5-dinitrile system present in 7a-d but was not previously detected.
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U2 - 10.1016/S0040-4020(97)00121-X
DO - 10.1016/S0040-4020(97)00121-X
M3 - Article
AN - SCOPUS:84961977858
SN - 0040-4020
VL - 53
SP - 4487
EP - 4496
JO - Tetrahedron
JF - Tetrahedron
IS - 12
ER -