Artículos de revistas
Axial/equatorial Populations In α-hetero-substituted Cyclohexanone Oximes And O-methyl Oximes
Registro en:
Magnetic Resonance In Chemistry. , v. 38, n. 8, p. 627 - 638, 2000.
7491581
2-s2.0-0034239438
Autor
Ribeiro D.S.
Olivato P.R.
Rittner R.
Institución
Resumen
Axial equatorial populations were determined for (E)-2-X-cyclohexanone oximes and O-methyl oxime ethers in chloroform by the Eliel method [X = F, Cl, Br, OCH3, N(CH3)2, SCH3]. A novel approach is presented, which uses 1H NMR data from the protons bonded to C-6. The conformational proportions were also obtained from the C-4 chemical shifts, the Z-isomer spectral parameters being taken as reference for calculation. For both series, all substituents adopt preferentially the axial conformation (86-96%), but the O-methyl oxime ethers present an enhanced axial population compared with the corresponding oximes, owing to the accepted occurrence of a πC=NOH//σ*CX stabilizing interaction. Copyright © 2000 John Wiley & Sons, Ltd. 38 8 627 638 Allinger, N.L., Allinger, J., Freiberg, L.A., Czaja, R.F., Lebel, N.A., (1960) J. Am. Chem. Soc., 82, p. 5876 Eliel, E.L., Allinger, N.L., Angyal, S.J., Morrison, C.A., (1965) Conformational Analysis, pp. 112-115. , Interscience: New York Basso, E.A., Kaiser, C., Rittner, R., Lambert, J.B., (1993) J. Org. Chem., 58, p. 7865 Saitô, H., Teresawa, I., Ohno, M., Nukada, K., (1969) J. Am. Chem. Soc., 91, p. 6696 Denmark, S.E., Dappen, M.S., (1984) J. Org. Chem., 49, p. 798 Denmark, S.E., Dappen, M.S., Sear, N.L., Jakobs, R.T., (1990) J. Am. Chem. Soc., 112, p. 3466 Olivato, P.R., Ribeiro, D.S., Rittner, R., Hase, Y., Del Pra, A., Bombieri, G., (1995) Spectrochim. Acta, Part A, 51, p. 1479 Eliel, E.L., (1959) Chem. Ind. (London), p. 568 Durand, R., Geneste, P., Moreau, C., Pavia, A.A., (1974) Org. Magn. Reson., 6, p. 73 Fraser, R.R., Capoor, R., Bovenkamp, J.W., La Croix, B.V., Pagoto, J., (1984) Can. J. Chem., 61, p. 2616 Dal Colle, M., Distefano, G., Modelli, A., Jones, D., Guerra, M., Olivato, P.R., Ribeiro, D.S., (1998) J. Phys. Chem. A, 102, p. 8037 Fraser, R.R., Dhawan, K.L., Taymaz, K., (1978) Org. Magn. Reson., 11, p. 269 Eliel, E.L., Wilen, S.H., Mander, L.N., (1994) Stereochemistry of Organic Compounds, p. 698. , Wiley: New York Eliel, E.L., Wilen, S.H., Mander, L.N., (1994) Stereochemistry of Organic Compounds, pp. 692-694. , Wiley: New York Riddell, F.G., (1974) Internal Rotation in Molecules, p. 24. , Orville-Thomas WJ (ed). Wiley: New York Basso, E.A., Kaiser, C., Rittner, R., Lambert, J.B., (1994) Magn. Reson. Chem., 32, p. 205 Geneste, P., Durand, R., Kamenka, J.-M., Beierbeck, H., Martino, R., Saunders, J.K., (1978) Can. J. Chem., 56, p. 1940 Rouillard, M., Girault, Y., Decouzon, M., Azzaro, M., (1983) Org. Magn. Reson., 21, p. 357 Hoogesteger, F.J., Grove, D.M., Jenneskers, L.W., De Bruin, T.J.M., Jansen, B.A.J., (1996) J. Chem. Soc., Perkin Trans., 2, p. 2327 Kalinowski, H.-O., Berger, S., Braun, S., (1988) Carbon-13 NMR Spectroscopy, pp. 109-110. , Wiley: New York Thorpe, J.W., Warkentin, J., (1973) Can. J. Chem. Soc., 51, p. 927 Allinger, N.L., Allinger, J., (1958) J. Am. Chem. Soc., 80, pp. 5476-5480 Scholz, D., (1983) Synthesis, p. 944 Ohno, M., Naruse, N., Torimitsu, S., Okamoto, M., (1966) Bull. Chem. Soc. Jpn., 39, p. 1119 Allinger, J., Allinger, N.L., (1958) Tetrahedron, 2, p. 64 Newman, M.S., Farbman, M.D., Hipsher, H., (1955) Org. Synth., Coll. Vol., 3, p. 188 Bousquet, E.W., (1943) Org. Syntl., Coll. Vol., 2, p. 313 Wrobel, J., Nelson, V., Surniejski, J., Kovacic, P., (1979) J. Org. Chem., 44, p. 2345 Ohno, M., Torimitsu, S., Naruse, N., Okamoto, M., Sakai, I., (1966) Bull. Chem. Soc. Jpn., 39, p. 1129 Hudlicky, M., Hokr, J., (1949) Collect. Czech. Chem. Commun., 14, p. 561 Chow, Y.L., Colón, C.J., (1968) J. Org. Chem., 33, pp. 2598-2601 Ziegenbein, W., Schäffler, A., Kaufhold, R., (1955) Chem. Ber., 88, p. 1906