Diethyl Oxalate → Ethyl 5-methyl-3-oxohexanoate

HRID 1063804Notes

Reaction equation

HRID 1063804 reaction equation
[Na].C(O[C:5](=O)[C:6]([O:8][CH2:9][CH3:10])=[O:7])C.[CH2:12]([C:16](C)=[O:17])[CH:13]([CH3:15])[CH3:14]>C(O)C>[CH2:9]([O:8][C:6](=[O:7])[CH2:5][C:16](=[O:17])[CH2:12][CH:13]([CH3:15])[CH3:14])[CH3:10]

Participants

5

Reactant 3

HCID 7268Diethyl OxalateHCID 7909Methyl Isobutyl KetoneHCID 5360545Sodium

Product 1

HCID 96344Ethyl 5-methyl-3-oxohexanoateYield 116.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
60 °C

Procedure

Sodium pellets (4.6 g, 200 mmol) were dissolved in ethanol (165 ml) under nitrogen at room temperature and a solution of diethyloxalate (13.5 ml, 100 mmol) in isobutylmethyl ketone (30 ml, 200 mmol) was added dropwise at room temperature over 20 minutes. The reaction was heated to 60° C. and stirred at this temperature for one hour. After cooling to room temperature the reaction was poured onto ice-cold 2N HCl (200 ml) and extracted with diethylether (4×200 ml). The combined organic extracts were washed with water, dried over MgSO4 and concentrated under reduced pressure to give 5-methyl-3-oxo-hexanoic acid ethyl ester (20 g) as a yellow oil. 1H NMR (400 MHz, CDCl3): δ=14.40-14.70 (1H, brs), 6.27 (1H, s), 4.25-4.32 (2H, quart), 2.26-2.31 (2H, d) (1H, m), 1.29-1.34 (3H, t), 0.89-0.94 (6H, d) ppm. LRMS (thermospray): m/z [M+NH4]+ 218.

Workup

  1. temperatureAfter cooling to room temperature the reaction
  2. additionwas poured onto ice-cold 2N HCl (200 ml)
  3. extractionextracted with diethylether (4×200 ml)
  4. washThe combined organic extracts were washed with water
  5. dry with materialdried over MgSO4
  6. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-029a417a885a428b9242c85417e51e1b
Source dataset
uspto-grants-2005_11
Patent number
US06967204B2

Reaction notes

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