caa a22 4500 463239288 CHVBK 20180405153307.0 cr unu---uuuuu 170326e20071101xx s 000 0 eng 10.1007/s10947-007-0168-8 doi (NATIONALLICENCE)springer-10.1007/s10947-007-0168-8 Benzyl group conformation in 4-benzyl-4-hydroxypiperidines [Elektronische Daten] [A. Manimekalai, T. Maruthavanan, K. Selvaraju, Ibon Alkorta] The high-resolution 1H and 13C NMR spectra of eight 4-benzyl-4-hydroxypiperidines 1-8 were recorded in CDCl3 and analyzed. In 2, the conformation of the equatorial benzyl group at C(4) was established as an equilibrium mixture of A [the phenyl group is gauche with respect to OH and C(5)] and B [the phenyl group is gauche with respect to OH and C(3)], whereas in 3-alkyl-4-benzyl-4-hydroxypiperidines 3-8, the favored conformation of the benzyl group at C(4) is A. In 1, the axial benzyl group at C(4) adopts the gauche conformations A′ [the phenyl group is gauche with respect to OH and C(3)] and B′ [the phenyl group is gauche with respect to OH and C(5)], in which the phenyl ring of the benzyl group is gauche with respect to the OH group. The HF/DFT B3LYP/6-3G* hybrid calculations of model systems 1′-3′ also support these conformations. The 13C data reveal that the equatorial methyl group at C(3) exerts a shielding influence on the methyl-bearing carbon and the magnitude of the α effect was found to be approximately −1.5 ppm. The parameters of the 13C substituent in the benzyl group show that the the α effect of the equatorial benzyl group is considerably higher in 3-ethyl tertiary alcohol 7 than in 3-methyl tertiary alcohol 3 and 4-benzyl-t(4)-hydroxypiperidine 2. This may be explained if we take into account the different conformations of the ethyl group in t(4)-hydroxy-3-ethyl-2,6-diphenylpiperidine 12 and 3-ethyl tertiary alcohol 7. Springer Science+Business Media, Inc., 2007 4-benzyl-4-hydroxypiperidines nationallicence 1H NMR nationallicence 13C NMR nationallicence configuration nationallicence conformation nationallicence Manimekalai A. Department of Chemistry, Annamalai University, 608 002, Annamalainagar, India aut Maruthavanan T. Department of Chemistry, SONASTARCH, Sona College of Technology, 636 005, Salem, India aut Selvaraju K. Department of Chemistry, Annamalai University, 608 002, Annamalainagar, India aut Alkorta Ibon Instituto de Quimica Medica, CSIC, Juan de la Clerva, 3, E-28006, Madrid, Spain aut Journal of Structural Chemistry Springer US 48/6(2007-11-01), 1036-1045 0022-4766 48:6<1036 2007 48 10947 https://doi.org/10.1007/s10947-007-0168-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10947-007-0168-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Manimekalai A. Department of Chemistry, Annamalai University, 608 002, Annamalainagar, India aut NATIONALLICENCE 700 1- Maruthavanan T. Department of Chemistry, SONASTARCH, Sona College of Technology, 636 005, Salem, India aut NATIONALLICENCE 700 1- Selvaraju K. Department of Chemistry, Annamalai University, 608 002, Annamalainagar, India aut NATIONALLICENCE 700 1- Alkorta Ibon Instituto de Quimica Medica, CSIC, Juan de la Clerva, 3, E-28006, Madrid, Spain aut NATIONALLICENCE 773 0- Journal of Structural Chemistry Springer US 48/6(2007-11-01), 1036-1045 0022-4766 48:6<1036 2007 48 10947 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer