Hydrochloric Acid → Ethyl 3-oxooxane-4-carboxylate

HRID 1169235Notes

Reaction equation

HRID 1169235 reaction equation
[CH2:1]([O:3][C:4](=[O:15])[CH2:5][CH2:6][CH2:7][O:8][CH2:9][C:10](OCC)=[O:11])[CH3:2].CC(C)([O-])C.[K+].O1CCCC1.Cl>C1(C)C=CC=CC=1>[CH2:1]([O:3][C:4]([CH:5]1[CH2:6][CH2:7][O:8][CH2:9][C:10]1=[O:11])=[O:15])[CH3:2]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8028TetrahydrofuranHCID 21362494Ethyl 4-(2-ethoxy-2-oxoethoxy)butanoateHCID 23665647Potassium tert-butoxide

Product 1

HCID 21362493Ethyl 3-oxooxane-4-carboxylateYield 48%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A solution of 4-ethoxycarbonylmethoxybutyric acid ethyl ester (90%, 15.0 g, 61.9 mmol) in toluene (300 mL) was stirred at room temperature and treated over 5 min with a solution of potassium tert-butoxide in tetrahydrofuran (1.0 M, 74.2 mL, 74.2 mmol). The mixture was stirred at room temperature for 24 h , then was poured into 1 N hydrochloric acid. The phases were separated, and the aqueous phase was extracted with ether. The combined organic phases were dried (Na2SO4), filtered and concentrated in vacuo. The residue was purified by flash column chromatography (5% ethyl acetate/hexanes) to provide the product as a pale yellow liquid (5.06 g, 48%). 1H NMR (300 mHz, CDCl3) δ11.85 (s, 1H), 4.24 (q, J=7.3 Hz, 2H), 4.14 (t, J=1.7 Hz, 2H), 3.79 (t, J=5.5 Hz, 2H), 2.35 (tt, J=5.5, 1.7 Hz, 2H), 1.32 (t, J=7.3 Hz, 3H).

Workup

  1. customThe phases were separated
  2. extractionthe aqueous phase was extracted with ether
  3. dry with materialThe combined organic phases were dried (Na2SO4)
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customThe residue was purified by flash column chromatography (5% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-e19cff4a0c814f4b8de3fd11ca3d8f50
Source dataset
uspto-grants-2003_09
Patent number
US06627629B2

Reaction notes

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