9-fluoro-11 beta,16 alpha,17,21-tetrahydroxypregna-1,4-diene-3,20-dione cyclic 16,17-acetal with acetone, 21-(3,3-dimethylbutyrate)
(11beta,16alpha)-21-(3,3-Dimethyl-1-oxobutoxy)-9-fluoro-11-hydroxy-16,17-((1-methylethylidene)bis(oxy))pregna-1,4-diene-3,20-dione