ISSN:
0030-4921
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Force field (MM2) calculations, 13C NMR substituent-induced shifts (SIS) and epimeric shift differences (ESD) indicate a preference for equatorial substituents in the 2-position, but equal eq/ax populations in the 1-position of tetralines. Similar conclusions are reached from Yb(fod)3-induced shifts, which are also used for signal assignments, e.g. in 1-tetralone. Configurational assignments are possible for 1,2- and 1,3-epimers (ESD up to 4 ppm) but, in line with the non-discriminating eq/ax conformations at C-I, not for 1,4-epimers (ESD〈0.5 ppm). More than 50 compounds were measured, including functional derivatives which show regular SIS for substituents in the aromatic moiety only for m- and p-carbon atoms. OMe, but not OH or OAc substituents, induce o-carbon SIS varying from -11 to -19 ppm. Conversion of 1-hydroxytetralin to esters induces shielding variations at the aromatic carbon atoms which indicate the electrostatic origin of derivatization shifts.
Additional Material:
8 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1270220310
