Carbon‐13 NMR studies. 96—carbon‐13 spectra of several polyhydroxylated 9,10‐dihydrophenanthrene and phenanthrene derivatives

The 13C spectra of eleven 9,10‐dihydrophenanthrene and twelve phenanthrene derivatives were recorded in order to examine the effects of hydroxy and methoxy substitution on the skeletal carbon shieldings. For each series, the parent compounds were the 2,4‐disubstituted derivatives with the others bearing 5‐, 6‐ and/or 7‐substituents, including the naturally occurring orchinol and loroglossol. The data should be helpful for examinations of related compounds. Some examples of particularly facile hydrogen‐deuterium exchange at aryl positions were encountered. Since these occur under apparently neutral conditions, suitable caution may be required in examinations of related compounds.