Use
Crystallise 5-cholanic acid from EtOH, Me2CO or AcOH. The ethyl ester has m 93-94o (from 80% EtOH), b 273o/12mm, [] D 20 +21o (CHCl3), and the methyl ester has m 86-87o (from MeOH) after purification through Al2O3 and eluting with *C6H6, and [] D 20 +21.2o (CHCl3). The 1H NMR (CDCl3) for the C18 & C19 protons has at 0.65 and 0.92ppm [see 5-cholanic acid above, Mandava et al. Steroids 23 357 1974]. [Stoll et al. Helv Chim Acta 18 644 1935, Huang-Minlon J Am Chem Soc 7 1 330 1949, Beilstein 9 III 2656, 9 IV 1992.]