ADDITIVITY RELATIONSHIPS IN THE C-13 NUCLEAR-MAGNETIC-RESONANCE SPECTRA OF POLYHYDROXY STEROIDS

delta(c) Values for the C-13 NMR spectra of polyhydroxy 5 alpha,14 alpha-steroids are. as a result of an additivity relationship, equivalent to the sum of the delta(c) values of the individual 1,2- and 1,3-glycols present in the molecule. Differences in the experimental delta(c) values (Delta delta(g)), reported for a variety of glycols, from those derived from addition of monohydroxy substituent effects, were converted into dihydroxy steroid parameters. Ancillary data for 8 beta-hydroxy steroids have also been derived. The dihydroxy steroid para meters were applied to 14 different types oi known polyhydroxy steroid (6-19) to provide calculated delta(c) values. The results-indicate that, within reasonable limits, this method generally predicts delta(c) values for polyhydroxy steroids which are close to those observed. except where there is severe steric hindrance present (e.g. as found in the 4 beta,6 beta,8 beta,15 beta-tetrahydroxylated steroid 19).