The glycoside dioscin from the Mexican wild yam root, Dioscorea, constituted the first significant sapogenin plant source for steroid drugs. Hydrolysis of this saponin leads to scission of the trisaccharide at the 3-position and the formation of the aglycone, diosgenin.
Oxidation by means of chromium trioxide leads to preferential attack at the electron-rich enol ether double bond. In effect, this transformation converts the side chain at C-17 in diosgenin to the acetyl group required for many steroid drugs.
Heating that intermediate in with alcoholic sodium hydroxide leads to the elimination of the ester grouping beta to the ketone; there is thus obtained 16-dehydropregnenolone acetate.
The presence of the olefin at C-17 allows ready entry to C-19 androstanes and provides the necessary function for the synthesis of potent C-16- and C-16,17-substituted corticosteroids.
^Liu MJ, Wang Z, Ju Y, Wong RN, Wu QY (2005). "Diosgenin induces cell cycle arrest and apoptosis in human leukemia K562 cells with the disruption of Ca2+ homeostasis". Cancer Chemother. Pharmacol.55 (1): 79–90. doi:10.1007/s00280-004-0849-3. PMID15372201.
^Goswami, A.; Kotoky, R.; Rastogi, R. C.; Ghosh, A. C. (2003). "A One-Pot Efficient Process for 16-Dehydropregnenolone Acetate". Organic Process Research & Development7 (3): 306. doi:10.1021/op0200625.edit