Smilagenone → epi-Sarsasapogenin

Participants

Reaction Conditions

Reaction Steps

A solution of lithium tri-tert-butoxyaluminohydride in THF (1M, 41.71 kg) was added (over ca. 2 hours) to a stirred solution of sarsasapogenone (17.38 kg,) in dry THF (ca 70 kg) at −23 to −30° C. under dry nitrogen. The process line was washed with THF and the mixture stirred at −23 to −30° C. for ca. 3 hours. The resulting solution was carefully quenched with aqueous aqueous sodium sulfate solution (5.67 kg in 28.67 kg of water). The inorganic salts were removed by filtration and washed with THF (184 kg). Water (63.18 kg) was added and the bulk of the THF was removed by distillation. Additional water (126.44 kg) was added and the product isolated by filtration. The product was washed with water (2×17.3.8 kg) and acetone (4×13.73 kg). The product was dried at 35-40° C. to afford episarsasapogenin (14.48 kg).

Provenance & Evidence