1alpha,3beta-Bis(tert-butyldimethylsilyloxy)-17-(tert-butoxycarbonylmethoxymethyl)androsta-5,7,16-triene → 1alpha,3beta-Bis(tert-butyldimethylsilyloxy)-17-(2-ethyl-2-hydroxybutoxymethyl)androsta-5,7,16-triene

HRID 1792209Notes

Reaction equation

HRID 1792209 reaction equation
[Si:1]([O:8][C@@H:9]1[C@@:26]2([CH3:27])[C:13](=[CH:14][CH:15]=[C:16]3[C@@H:25]2[CH2:24][CH2:23][C@@:21]2([CH3:22])[C@H:17]3[CH2:18][CH:19]=[C:20]2[CH2:28][O:29][CH2:30][C:31](OC(C)(C)C)=[O:32])[CH2:12][C@@H:11]([O:38][Si:39]([C:42]([CH3:45])([CH3:44])[CH3:43])([CH3:41])[CH3:40])[CH2:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[CH2:46]([Mg]Br)[CH3:47].O1CC[CH2:52][CH2:51]1>O1CCCC1>[Si:1]([O:8][C@@H:9]1[C@@:26]2([CH3:27])[C:13](=[CH:14][CH:15]=[C:16]3[C@@H:25]2[CH2:24][CH2:23][C@@:21]2([CH3:22])[C@H:17]3[CH2:18][CH:19]=[C:20]2[CH2:28][O:29][CH2:30][C:31]([CH2:46][CH3:47])([OH:32])[CH2:51][CH3:52])[CH2:12][C@@H:11]([O:38][Si:39]([C:42]([CH3:43])([CH3:45])[CH3:44])([CH3:41])[CH3:40])[CH2:10]1)([C:4]([CH3:5])([CH3:6])[CH3:7])([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 673017221alpha,3beta-Bis(tert-butyldimethylsilyloxy)-17-(tert-butoxycarbonylmethoxymethyl)androsta-5,7,16-trieneHCID 178420660HCID 178420660, compound

Product 1

HCID 696301361alpha,3beta-Bis(tert-butyldimethylsilyloxy)-17-(2-ethyl-2-hydroxybutoxymethyl)androsta-5,7,16-trieneYield 81.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of 1α,3β-bis(tert-butyldimethylsilyloxy)-17-(tert-butoxycarbonylmethoxymethyl)androsta-5,7,16-triene (175 mg, 0.266 mmol) in tetrahydrofuran (4 ml) was subjected to reaction with a 0.96M ethylmagnesium bromide/tetrahydrofuran solution (3 ml, 2.88 mmol) using a procedure similar to that of Example 27(2) (external temperature of −30° C. for 1.5 hours), worked up and purified by preparative thin layer chromatography (3 sheets (each 0.5 mm thickness), hexane:ethyl acetate=20:1, developed twice, hexane:ethyl acetate=15:1, developed twice, and hexane:ethyl acetate=10:1, developed once) to give the titled compound (139.5 mg, 81%) as a colorless oil.

Workup

  1. customof Example 27(2) (external temperature of −30° C. for 1.5 hours)
  2. custompurified by preparative thin layer chromatography (3 sheets (each 0.5 mm thickness), hexane

Sources & evidence

ORD record
ord-6c03d50094e243f4919677055cf73518
Source dataset
uspto-grants-2006_07
Patent number
US07074777B2

Reaction notes

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