HCID 22875683, compound → HCID 22875682, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 20-tert-butyldimethylsilyloxy-7-methyl-pregn-5-ene-3,7-diol (298 gm, 0.59 mol, product of Step 4) in toluene (3 L) and cyclohexanone (1.03 L) was azeotroped to remove 750 mL of solvent. A solution of aluminum isopropoxide (121 gm) in toluene (620 mL) was added and the solution azeotroped to remove another 650 mL of solvent. A reflux condenser was added and the solution refluxed overnight. The solution was cooled to 40° C. and Supercell™ (125 gm) and water (125 mL) were added. After stirring for 10 min, the mixture was filtered and the solids washed with toluene (550 mL). The solvent was removed by rotoevaporation to yield a orange liquid which was purified by column chromatography on silica gel eluted with hexane, followed by 5-10% ethyl acetate in hexanes. The title compound was isolated as a mixture of 20α- and 20β-isomers.

Provenance & Evidence