Acetic Anhydride → 21-Acetoxy-3,3-ethylenedioxy-20-nitropregna-5,16-dien-9alpha-ol

Participants

Reaction Steps

Acetic anhydride (1.5 ml) was added to a stirred suspension of 3,3-ethylenedioxy-20-nitropregna-5,16-diene-9α,21-diol (1.00 g of diastereomer II, prepared according to example 2), and 4-dimethylaminopyridine (100 mg) in methylene chloride (10 ml) to give a clear solution. The reaction mixture was stirred for an additional 30 minutes and concentrated under reduced pressure. The residue was dissolved in methylene chloride and filtered over a silica gel column. The filtrate was evaporated under reduced pressure to afford a white solid which was dried under reduced pressure at 50° C.

Provenance & Evidence