Treatment of dexamethasone (I) with trimethyl orthocyclopropanecarboxylate (II) in the presence of p-toluenesulfonic acid gives the mixed orthoester (III), which, upon acidic hydrolysis with oxalic acid leads to the C-17 cyclopropanecarboxylate ester (IV). Subsequent esterification of (IV) with cyclohexanecarbonyl chloride (V) furnishes the desired dexamethasone diester.