SOLVENT EFFECT IN NMR ENANTIOMERIC ANALYSIS USING (S)-1,1'-BINAPHTHYL-2,2'-DIOL AS A CHIRAL SOLVATING AGENT

The determination of the enantiomeric composition of chiral compounds by H-1, C-13, and P-31 NMR spectroscopy in the presence of (S)-1,1'-bi naphthyl-2,2'-diol demonstrates that the enantioselectivity of the met hod increases when the polarity of a solvent decreases as follows: CD3 OD-D2O (4 : 1) < CD3OD < CDCl3 < CDCl3-CCl4 (1 : 1) < C6D6. The effect is caused by increase in stability of solvating agent-substrate compl exes formed through the hydrogen bonds. Pantolactone, esters of substi tuted cyclopropanecarboxylic acids, amino alcohol propranolol, and 2,2 '-bis(diphenylphosphinyl)-1, 1'-binaphthyl were used as the substrates .