3-tert-Butyldimethylsilyloxy Pregnenolone → (3S,8S,9S,10R,13S,14S,17S)-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-3-[(1,1-dimethylethyl)dimethylsilyloxy]-17-((S)-2-hydroxy-6-methylhept-6-en-2-yl)-10,13-dimethyl-1H-cyclopenta[a]phenanthrene

Participants

Reaction Steps

The coupling reaction of the protected pregnenolone 1 (500.0 mg, 1.16 mmol) with 5-bromo-2-methyl-1-pentene 9 (199.0 mg, 1.22 mmol) in the presence of samarium diiodide was performed under similar condition as described for the preparation of 2 to afford the 20S-hydroxy steroid 10 (419.0 mg, 0.82 mmol, 71%) as a white powder.

Provenance & Evidence