(2S)-2-((8S,9S,10R,13S,14S,17R)-10,13-dimethyl-3-oxo-1,2,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopenta(a)phenanthren-17-yl)propanal → HCID 11142115, compound

Participants

Reaction Conditions

Reaction Steps

i)—A solution of (20S)-3-oxopregn-4-ene-20-carboxaldehyde (125 g) in dry ethanol (1250 ml) was cooled to −10° C., whereupon a solution of sodium borohydride (4.4 g) in dry ethanol (80 ml) was added in 30 min. After stirring the mixture for 2 hours at −10° C., the reaction was quenched by adding a 50% aqueous solution of acetic acid. The reaction mixture was concentrated under reduced pressure to 25% of its original volume and then poured into ice-water (5 l). The resulting suspension was stirred overnight and filtered. The residue was washed with water and dried to give (20S)-21-hydroxy-20-methylpregn-4-en-3-one (124 g) which was used in the following step without further purification.

Provenance & Evidence