Perchloric Acid → (11β,16β)-11-Chloro-17,21-dihydroxy-16-methylpregna-1,4-diene-3,20-dione

Participants

Reaction Steps

A solution of 21-acetoxy-11β-chloro-17-hydroxy-16β-methylpregna-1,4-diene-3,20-dione (100 mg.) in methanol (7 ml.) was treated with 60% aqueous perchloric acid (0.2 ml.) at room temperature. After 24 hours sodium acetate (100 mg.) was added and about half of the solvent was evaporated in vacuo. Purification of the remaining solution by preparative thin layer chromatography and crystallisation from methanol afforded 11β-chloro-17,21-dihyroxy-16β-methylpregna-1,4-diene-3,20-dione as needles, m.p. 202°-204° decomp (Kofler).

Provenance & Evidence