(E)-Methyl 3alpha-acetoxy-5beta-chol-9(11),16,22-trien-24-oate → (R)-Methyl 4-((3R,5R,8S,10S,13R,14S,17R)-3-acetoxy-10,13-dimethyl-2,3,4,5,6,7,8,10,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl)pentanoate

Participants

Reaction Steps

To a solution of compound 1.7a (17.5 g, 41 mmol) in EtOAc (350 mL) was added PtO2 (4.37 g), and the resulting slurry was hydrogenated in a Parr apparatus (70 psi) for 14-16 h. At this point the reaction was determined to be complete by TLC. The mixture was filtered through a small plug of diatomaceous earth (CELITE®) and the solvent was removed under vacuum, affording compound 1.8a (17.0 g, 96.0%) as a white solid. The above product was used in the next step without further purification.

Provenance & Evidence