Isobutylene oxide → 1alpha,3beta-Bis(tert-butyldimethylsilyloxy)-20-hydroxy-20-methylpregna-5,7,16-triene

HRID 1792194Notes

Reaction equation

HRID 1792194 reaction equation
[Si:1]([O:8][C@@H:9]1[C@@:29]2([CH3:30])[C:13](=[CH:14][CH:15]=[C:16]3[C@@H:28]2[CH2:27][CH2:26][C@@:25]2([CH3:31])[C@H:17]3[CH2:18][CH:19]=[C:20]2[C:21]([OH:24])([CH3:23])[CH3:22])[CH2:12][C@@H:11]([O:32][Si:33]([C:36]([CH3:39])([CH3:38])[CH3:37])([CH3:35])[CH3:34])[CH2:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[H-].[K+].C1OCCOC2C(=CC=CC=2)OCCOCCOC2C(=CC=CC=2)OC1.[O:68]1[C:70]([CH3:72])([CH3:71])[CH2:69]1>C1(C)C=CC=CC=1.C(OCC)(=O)C.O>[Si:1]([O:8][C@@H:9]1[C@@:29]2([CH3:30])[C:13](=[CH:14][CH:15]=[C:16]3[C@@H:28]2[CH2:27][CH2:26][C@@:25]2([CH3:31])[C@H:17]3[CH2:18][CH:19]=[C:20]2[C:21]([O:24][CH2:69][C:70]([OH:68])([CH3:72])[CH3:71])([CH3:23])[CH3:22])[CH2:12][C@@H:11]([O:32][Si:33]([C:36]([CH3:39])([CH3:38])[CH3:37])([CH3:34])[CH3:35])[CH2:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[Si:1]([O:8][C@@H:9]1[C@@:29]2([CH3:30])[C:13](=[CH:14][CH:15]=[C:16]3[C@@H:28]2[CH2:27][CH2:26][C@@:25]2([CH3:31])[C@H:17]3[CH2:18][CH:19]=[C:20]2[C:21]([OH:24])([CH3:23])[CH3:22])[CH2:12][C@@H:11]([O:32][Si:33]([C:36]([CH3:39])([CH3:38])[CH3:37])([CH3:34])[CH3:35])[CH2:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]

Participants

9

Reactant 4

HCID 11208Isobutylene oxideHCID 26541Dibenzo-18-crown-6HCID 82127Potassium hydrideHCID 696299251alpha,3beta-Bis(tert-butyldimethylsilyloxy)-20-hydroxy-20-methylpregna-5,7,16-triene

Product 2

HCID 696299251alpha,3beta-Bis(tert-butyldimethylsilyloxy)-20-hydroxy-20-methylpregna-5,7,16-trieneYield 38%HCID 696304801alpha,3beta-Bis(tert-butyldimethylsilyloxy)-20-(2-hydroxy-2-methylpropoxy)-20-methylpregna-5,7,16-trieneYield 19%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
45 °C

Procedure

A solution of 1α,3β-bis(tert-butyldimethylsilyloxy)-20-hydroxy-20-methylpregna-5,7,16-triene (49.2 mg, 0.0859 mmol), potassium hydride (35% in oil, 0.1 ml, 0.873 mmol) and dibenzo-18-crown-6 (30 mg, 0.0832 mmol) in toluene (0.2 ml) was stirred at room temperature for 3 min., 1,2-epoxy-2-methylpropane (60 mg, 0.832 mmol) was added and stirred at external temperature of 45° C. for 1.5 hours. The reaction solution was cooled with ice and water was added. The mixture was diluted with ethyl acetate, washed with saturated brine and the organic layer was dried over anhydrous magnesium sulfate. After evaporating under reduced pressure to remove the solvent, the thus obtained residue was purified by preparative thin layer chromatography (2 sheets (each 0.5 mm thickness), hexane:ethyl acetate=15:1, developed twice) to give the titled compound (10.4 mg, 19%) and 1α,3β-bis(tert-butyldimethylsilyloxy)-20-hydroxy-20-methylpregna-5,7,16-triene (18.6 mg, 38%), each as a colorless oil.

Workup

  1. additionwas added
  2. washwashed with saturated brine
  3. dry with materialthe organic layer was dried over anhydrous magnesium sulfate
  4. customAfter evaporating under reduced pressure
  5. customto remove the solvent
  6. customthe thus obtained residue was purified by preparative thin layer chromatography (2 sheets (each 0.5 mm thickness), hexane

Sources & evidence

ORD record
ord-bd7ab9dca243408ba0348a1cfe8114b5
Source dataset
uspto-grants-2006_07
Patent number
US07074777B2

Reaction notes

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