How is Fluticasone (CAS: 90566-53-3) typically synthesized?

Fluticasone is synthesized via a multi-step process, often involving the reduction of a tetrahydrofuran derivative to form the key intermediate. This intermediate is then reacted with 2,2,2-trifluoro-1,1-dichloroethane to yield the desired compound. The synthesis typically requires the use of hydrogen, sodium borohydride, and trifluoroacetic anhydride. The overall yield is generally between 60-70%, with high selectivity towards the target product.