Acetic Acid → HCID 178454384, compound

HRID 1774391Notes

Reaction equation

HRID 1774391 reaction equation
C(NC(C)C)(C)C.[CH2:8]([O:15][C:16]([CH2:18][C@H:19]1[CH2:24][CH2:23][C@H:22]([O:25][Si:26]([C:29]([CH3:32])([CH3:31])[CH3:30])([CH3:28])[CH3:27])[CH2:21][CH2:20]1)=[O:17])[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.[CH3:33][CH:34]([CH3:47])[C:35](=[O:46])[C:36]([O:38][CH2:39][C:40]1[CH:45]=[CH:44][CH:43]=[CH:42][CH:41]=1)=[O:37].C(O)(=O)C>O1CCCC1.CCCCCC.C(OCC)(=O)C>[Si:26]([O:25][C@H:22]1[CH2:23][CH2:24][C@H:19]([CH:18]([C:16]([O:15][CH2:8][C:9]2[CH:10]=[CH:11][CH:12]=[CH:13][CH:14]=2)=[O:17])[C:35]([OH:46])([CH:34]([CH3:33])[CH3:47])[C:36]([O:38][CH2:39][C:40]2[CH:41]=[CH:42][CH:43]=[CH:44][CH:45]=2)=[O:37])[CH2:20][CH2:21]1)([C:29]([CH3:32])([CH3:31])[CH3:30])([CH3:28])[CH3:27]

Participants

7

Reactant 4

HCID 176Acetic AcidHCID 7912DiisopropylamineHCID 11160044Benzyl 3-methyl-2-oxobutanoateHCID 178455316HCID 178455316, compound

Product 1

HCID 178454384HCID 178454384, compoundYield 29%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent3×HCID 21226206Ethyl acetate hexaneSolvent

Conditions

Temperature
-78 °C

Procedure

To a solution of diisopropylamine (418 mg, 4.15 mmol) in anhydrous tetrahydrofuran (6 mL) under the atmosphere of argon was added a 1.58 M n-butyl lithium-hexane solution (2.5 mL, 5.4 mmol) with stirring under ice cooling, and the mixture was stirred at 0° C. for 10 min, and then at −78° C. for 5 min. A solution of trans-4-benzyloxycarbonylmethyl-1-t-butyldimethylsilyloxycyclohexan (1.36 g, 3.76 mmol) in anhydrous tetrahydrofuran (7 mL) was added dropwise at the same temperature over 7 min, and the reaction mixture was further stirred for 15 min. The cold enolate solution thus prepared was added dropwise via canula to a solution of benzyl 3-methyl-2-ketobutyrate (776 mg, 3.76 mmol) in anhydrous tetrahydrofuran (4 mL) having been cooled to −78° C. After stirring at −78° C. for 1 h, the reaction mixture was adjusted to pH 4 with acetic acid, and the temperature was raised to room temperature. The reaction solvent was evaporated under reduced pressure, and the residue was diluted with ethyl acetate and water to separate the phases for extraction. The aqueous layer was extracted again with ethyl acetate, and the combined organic layer was concentrated under reduced pressure and the residue thus obtained was subjected to silica gel column chromatography (hexane-ethyl acetate 20:1) to give dibenzyl 3-(trans-4-t-butyldimethylsilyloxycyclohexyl)-2-hydroxy-2-isopropylsuccinate as oil in amounts of 629 mg (low polar diastereomer, yield: 29%) and 801 mg (high polar diastereomer, yield: 37%), respectively.

Workup

  1. stirringthe mixture was stirred at 0° C. for 10 min
  2. stirringthe reaction mixture was further stirred for 15 min
  3. stirringAfter stirring at −78° C. for 1 h
  4. temperaturethe temperature was raised to room temperature
  5. customThe reaction solvent was evaporated under reduced pressure
  6. additionthe residue was diluted with ethyl acetate and water
  7. customto separate the phases
  8. extractionfor extraction
  9. extractionThe aqueous layer was extracted again with ethyl acetate
  10. concentrationthe combined organic layer was concentrated under reduced pressure
  11. customthe residue thus obtained

Sources & evidence

ORD record
ord-b5c199378abf46148ce4cb11a133af2a
Source dataset
uspto-grants-2016_02
Patent number
US09260375B2

Reaction notes

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