O. Korver, M. Gorkom
1974
Citations
0
Influential Citations
15
Citations
Journal
Tetrahedron
Abstract
CD spectra at 25° and −185° and in various solvents are reported for 5 2-methyl substituted carboxylic acids i.e.: (R)-2-methylbutanoic acid (R)-2-hydroxy-2-methylbutanoic acid (R)-2-methoxy-2-methylbutanoic acid (R)-2-ethyl-2-methylbutanoic acid (2R,3S)-3-methoxy-2-methylbutanoic acid. The chiroptical properties are interpreted on the basis of reasonable assumptions about the rotamer populations and may be correlated with an empirical rule correlating the sign of the n→π* CD band of the carboxylic acid group and the spatial configuration around this group. NMR measurements on mixtures of the methyl esters and optically active shift reagents are described and use is made of these data to determine the optical purity.