caa a22 4500 467993106 CHVBK 20180323112550.0 cr unu---uuuuu 170328e19900801xx s 000 0 eng 10.1007/BF00480865 doi (NATIONALLICENCE)springer-10.1007/BF00480865 Aliev A. Patrice Lumumba Peoples' Friendship University, 117198, Moscow aut Determination of the orientation of the phenyl substituent in isomeric 1-ethyl-2,5-dimethyl-4-phenyl-4-piperidinols by two-dimensional nuclear overhauser effect (NOESY) spectroscopy. Conformation of the β isomer of 1,2,5-trimethyl-4-phenyl-4-piperidinol [Elektronische Daten] [A. Aliev] In the case of three isomers (α, Β, and γ) of 1-ethyl-2,5-dimethyl-4-phenyl-4-piperidinol it is shown that NOESY spectroscopy can be successfully used in the determination of the orientation of the phenyl substituent. It was observed that the chemical shifts of the protons and the carbon atoms in the ortho position and of the quaternary C atom of the phenyl substituent and the $$^1 J_{(C_{\left( 5 \right)} H_{(5a} )}$$ , direct spin-spin coupling constant (SSCC) satisfactory reflect the change in the orientation of the phenyl substituent on passing from the a isomer to the β and γ isomers. A chair 2a5e) ⇄ twist-boat (2e, 5e) conformational equilibrium in which the twist-boat conformation is stabilized by an intramolecular hydrogen bond is proposed for the Β isomer of 1,2,5-trimethyl-4-phenyl-4-piperidinol on the basis of the NMR data. Plenum Publishing Corporation, 1991 Chemistry of Heterocyclic Compounds Kluwer Academic Publishers-Plenum Publishers 26/8(1990-08-01), 894-897 0009-3122 26:8<894 1990 26 10593 https://doi.org/10.1007/BF00480865 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00480865 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Aliev A. Patrice Lumumba Peoples' Friendship University, 117198, Moscow aut NATIONALLICENCE 773 0- Chemistry of Heterocyclic Compounds Kluwer Academic Publishers-Plenum Publishers 26/8(1990-08-01), 894-897 0009-3122 26:8<894 1990 26 10593 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer