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

HRID 910005Notes

Reaction equation

HRID 910005 reaction equation
[CH3:1][C:2]([Si:5]([CH3:30])([CH3:29])[O:6][C@@H:7]1[CH2:23][C:22]2[C@@:10]([CH3:28])([C@@H:11]3[C@@H:19]([CH2:20][CH:21]=2)[C@H:18]2[C@@:14]([CH3:27])([C@@H:15]([C:24](=[O:26])[CH3:25])[CH2:16][CH2:17]2)[CH2:13][CH2:12]3)[CH2:9][CH2:8]1)([CH3:4])[CH3:3].Br[CH2:32][CH2:33][CH2:34][C:35]([CH3:37])=[CH2:36].[I-].[I-].[Sm+2]>>[CH3:4][C:2]([Si:5]([CH3:30])([CH3:29])[O:6][C@@H:7]1[CH2:23][C:22]2[C@@:10]([CH3:28])([C@@H:11]3[C@@H:19]([CH2:20][CH:21]=2)[C@H:18]2[C@@:14]([CH3:27])([C@@H:15]([C@@:24]([OH:26])([CH2:32][CH2:33][CH2:34][C:35]([CH3:37])=[CH2:36])[CH3:25])[CH2:16][CH2:17]2)[CH2:13][CH2:12]3)[CH2:9][CH2:8]1)([CH3:1])[CH3:3]

Participants

4

Reactant 3

HCID 108845053-tert-Butyldimethylsilyloxy PregnenoloneHCID 117895385-Bromo-2-methyl-1-penteneHCID 178506586HCID 178506586, compound

Product 1

HCID 66899745(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]phenanthreneYield 71%

Procedure

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.

Workup

  1. customas described for the preparation of 2

Sources & evidence

ORD record
ord-1356ed6f810e4a77bc5aa66a55a38320
Source dataset
uspto-grants-2011_09
Patent number
US08022052B2

Reaction notes

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