The Palladium Catalyzed Hydrogenation of Cholesterol

Reduction of Serum Cholesterol with Sitostanol-Ester Margarine in a Mildly Hypercholesterolemic Population

“…The Sitostanol fatty acid ester mixture is prepared by hardening or hydrogenating a commercial B-sitosterol mixture (sitosterol=24-ethyl-5C.-cholestane-3B-ol). B-sitostanol can be prepared by a prior known cholesterol hardening tech nique by hardening B-Sitosterol by means of a Pd/C catalyst in an organic solvent (43). A hardening degree of over 99% is achieved in the reaction.…”

Synthesis of derivatives of <em>β</em>-sitosterol and evaluation of their anti-bacterial activity

“…β-Sitosterol was subjected to hydrogenation over Pd/C in methanol at room temperature under a hydrogen atmosphere to yield compound 3 in 96% yield. Augustine and Reardon report that Pd is the best catalyst to perform hydrogenation of sterols due to its reactivity and ability to give the pure isomeric product (Augustine and Reardon, 1969). Spectral signals of this compound showed the absence of peaks that arise due to the C6 olefinic proton in 1 H-NMR at 5.33 ppm and C=C stretching peaks at 1654 cm -1 in IR confirmed loss of unsaturation during the reaction.…”

“…Compound 3 was synthesized according to the modified procedure described by Augustine and Reardon, (1969). A mixture of compound 1 (30 mg, 0.0723 mmol) in anhydrous methanol (2.79 mL) was hydrogenated over palladium on 499 charcoal (1.5 mg, 5%) at room temperature.…”

Chemical Reaction Engineering of Biomass Conversion

“…When looking at the list of catalysts being successful, it is striking to notice that only few catalyst metals seem to be of importance. For the double bond hydrogenation and hydrogenolysis of hydroxyl groups, Pd is both active and selective (Augustine and Reardon, 1969). For the hydrogenation of the carboxyl group (e.g., production of sugar alcohols), sponge nickel (Raney nickel) and Ru on active carbon work well, but Raney nickel is probably going to be replaced by Ru because of environmental and health reasons.…”