“…This latter undesirable feature is compensated for by formation of the 16,17-acetonide (IV), with the resulting compound having markedly increased topical activity. 3,4,5 These observations suggested that further modification, with formation of the 6a,9a-difluoro-16a-hydroxyprednisolone (V) and, for topical use, the corresponding 16,17-acetonide (VI), might be expected to combine highest antiinflammatory action with low sodium retention. This new corticosteroid, fluocinolone acetonide (VI), was synthesized.…”