Diethyl Ether → Isobutyl (E)-4-oxo-2-butenoate

HRID 1589800Notes

Reaction equation

HRID 1589800 reaction equation
[Cr](Cl)([O-])(=O)=O.[NH+]1C=CC=CC=1.[OH:12][CH2:13]/[CH:14]=[CH:15]/[C:16]([O:18][CH2:19][CH:20]([CH3:22])[CH3:21])=[O:17].C(OCC)C>ClCCl>[O:12]=[CH:13]/[CH:14]=[CH:15]/[C:16]([O:18][CH2:19][CH:20]([CH3:22])[CH3:21])=[O:17]

Participants

5

Reactant 3

HCID 3283Diethyl EtherHCID 11819298isobutyl (E)-4-hydroxycrotonateHCID 178418287HCID 178418287, compound

Product 1

HCID 10057752Isobutyl (E)-4-oxo-2-butenoateYield 91.8%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a suspension of pyridinium chlorochromate (100 g, 0.463 mol) in dichloromethane (350 ml), a solution of isobutyl (E)-4-hydroxycrotonate (50 g, 0.316 mol) in dichloromethane (150 ml) was added. The internal temperature gradually rose to 40° C. and stirring was continued for 2 hours without cooling. Diethyl ether (0.9 l) was added and the supernatant was decanted from the black gum. The insoluble residue was washed twice with 300 ml portions of diethyl ether. The combined organic solutions were passed through a short pad of Florisil and the solvent was removed by distillation, to yield 45.3 g (91.6%) of the title compound, as a pale yellow oil, Rf=0.5 (silica gel plates, cyclohexane-ethyl acetate 6:4). NMR (CDCl3): deltaH =9.80 (ABX, 1H, CHO), 6.98 and 6.75 (ABX, JAB =15 Hz, 2H, CH=CH). MS (E.I., 70 eV, 1.5 mA) m/z=155 (M-H)+, 85 (M-C3H3O2)+.

Workup

  1. customgradually rose to 40° C.
  2. temperaturewithout cooling
  3. customthe supernatant was decanted from the black gum
  4. washThe insoluble residue was washed twice with 300 ml portions of diethyl ether
  5. customthe solvent was removed by distillation

Sources & evidence

ORD record
ord-bf84af63136a443a884b47b8fdd3bf7d
Source dataset
uspto-grants-1993_04
Patent number
US05200406

Reaction notes

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