to isomer Id, as shown in Chart I. Examination of the 13C NMR spectra of isomers la-d corroborates these assignments. In each, the terminal methyl of the n-heptyl group appears at approximately 14.4 ppm, and there are two other signals above 25 ppm. One of these is likely to be the penultimate methylene of the n-heptyl group, and the other is the C5 methyl group. In la, lb, and Id, these two signals are close together at approximately 23 ppm, 13 ...
