2,2,2-Trifluoroethyl butanoate → 17alpha-Hydroxy-21-butanoyloxy-pregna-4-ene-3,20-dione

Participants

Reaction Steps

A mixture of 1 g of 17α,21-dihydroxy-pregna-4-ene-3,20-dione and 10 ml of trifluoroethyl butanoate in 50 ml of methyl ethyl ketone was reacted at 45° C. in the presence of 5 g of Candida cylindracea lipase for 8-10 hours, adding at regular time intervals 1 g of lipase. After completion of the reaction, the lipase was filtered off, the filtrate was concentrated under vacuum, taking up the residue three times with solvent. The semi-solid residue was purified by chromatography on a silica gel column with a dichloromethane/methanol 99:1 mixture. The richer fraction was evaporated to obtain 0.89 g (2.14 mM) of 17α-hydroxy-21-butanoyloxy-pregna-4-ene-3,20-dione.

Provenance & Evidence