@article{CsuetoertoekiSzatmariHeydenreichetal.2012, author = {Csuetoertoeki, Renata and Szatmari, Istvan and Heydenreich, Matthias and Koch, Andreas and Starke, Ines and Fueloep, Ferenc and Kleinpeter, Erich}, title = {Novel piperidine-fused benzoxazino- and quinazolinonaphthoxazines-synthesis and conformational study}, series = {TETRAHEDRON}, volume = {68}, journal = {TETRAHEDRON}, number = {31}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {OXFORD}, issn = {0040-4020}, doi = {10.1016/j.tet.2012.05.048}, pages = {6284 -- 6288}, year = {2012}, abstract = {The reactions of 1-(amino(2-hydroxyphenyl)methyl)-2-naphthol (3) and 1-(amino(2-aminophenyl) methyl)-2-naphthol (6) with glutardialdehyde resulted in the formation of piperidine-fused benzox-azinonaphthoxazine 4 and quinazolinonaphthoxazine 7, respectively, both in diastereopure form. The full conformational search protocols of 4 and 7 were successfully carried out by NMR spectroscopy and accompanying molecular modelling; the global minimum-energy conformers of all diastereomers were computed, and the assignments of the most stable stereoisomers, G(tct)(1) for 4 and G(tct)(1) for 7, were corroborated by spatial NOE information relating to the H-7a-H-10a-H-15b and H,H coupling patterns of the protons in the flexible part of the piperidine moiety. Additionally, mass spectrometric fragmentation was investigated in collision-induced dissociation experiments. The elemental compositions of the ions were determined by accurate mass measurements. (C) 2012 Elsevier Ltd. All rights reserved.}, language = {en} }