Cerium(III) chloride → (S)-tert-butyl 1-(tert-butyldimethylsilyloxy)-3-cyclopropylbut-3-en-2-yl(2-oxopent-3-enyl)carbamate

HRID 627247Notes

Reaction equation

HRID 627247 reaction equation
[Cl-].[Ce+3].[Cl-].[Cl-].[CH:5](/[Mg]Br)=[CH:6]\[CH3:7].[Si:10]([O:17][CH2:18][C@@H:19]([N:25]([CH2:33][C:34](N(OC)C)=[O:35])[C:26](=[O:32])[O:27][C:28]([CH3:31])([CH3:30])[CH3:29])[C:20]([CH:22]1[CH2:24][CH2:23]1)=[CH2:21])([C:13]([CH3:16])([CH3:15])[CH3:14])([CH3:12])[CH3:11]>C1COCC1>[Si:10]([O:17][CH2:18][C@@H:19]([N:25]([CH2:33][C:34](=[O:35])[CH:5]=[CH:6][CH3:7])[C:26](=[O:32])[O:27][C:28]([CH3:30])([CH3:29])[CH3:31])[C:20]([CH:22]1[CH2:23][CH2:24]1)=[CH2:21])([C:13]([CH3:15])([CH3:14])[CH3:16])([CH3:12])[CH3:11]

Participants

5

Reactant 3

HCID 24636Cerium(III) chlorideHCID 131735294(S)-tert-butyl 1-(tert-butyldimethylsilyloxy)-3-cyclopropylbut-3-en-2-yl(2-(methoxy(methyl)amino)-2-oxoethyl)carbamate2×HCID 178456052HCID 178456052, compound

Product 1

HCID 131735295(S)-tert-butyl 1-(tert-butyldimethylsilyloxy)-3-cyclopropylbut-3-en-2-yl(2-oxopent-3-enyl)carbamateYield 84%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

A suspension of cerium (III) chloride (27.8 g, 112.95 mmol) in THF (100 mL) at room temperature was stirred vigorously for 2 hours. The suspension was cooled to −78° C. and (E)-prop-1-enylmagnesium bromide (0.5 M in THF) (226 mL, 112.95 mmol) was added dropwise. The mixture was stirred at −78° C. for 1.5 hours. (S)-tert-butyl 1-(tert-butyldimethylsilyloxy)-3-cyclopropylbut-3-en-2-yl(2-(methoxy(methyl)amino)-2-oxoethyl)carbamate (Intermediate 235, 5 g, 11.30 mmol) in THF (20 mL) was then added dropwise at −78° C. The reaction was stirred at −78° C. for 30 minutes and then warmed to 0° C. for 15 minutes. The reaction was quenched with 10% citric acid, diluted further with water and extracted twice with ether. The organics were washed once with brine, dried over magnesium sulfate, filtered and concentrated. Silica gel chromatography (0%-20% ethyl acetate/hexanes) afforded the title compound as a light yellow oil (4.0 g, 84%).

Workup

  1. stirringThe mixture was stirred at −78° C. for 1.5 hours
  2. stirringThe reaction was stirred at −78° C. for 30 minutes
  3. temperaturewarmed to 0° C. for 15 minutes
  4. customThe reaction was quenched with 10% citric acid
  5. additiondiluted further with water
  6. extractionextracted twice with ether
  7. washThe organics were washed once with brine
  8. dry with materialdried over magnesium sulfate
  9. filtrationfiltered
  10. concentrationconcentrated

Sources & evidence

ORD record
ord-8db0b1385bfe4d74a14f588c3d510512
Source dataset
uspto-grants-2016_04
Patent number
US09309245B2

Reaction notes

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