abstract |
Flumethasone (6a, 9a-difluoro-11β, 17a, 21-trihydroxy-16a-methyl-pregna-1,4-diene-3,20-dione), flumethasone 21-acetate, or its 17-carboxylandrostene analog Comprising reacting a compound of formula (IIIa) with an electrophilic fluorinating reagent. |