Acetic Acid → Dimethyl(2-oxo-3,6-dimethyl-5-heptenyl)phosphonate

HRID 371451Notes

Reaction equation

HRID 371451 reaction equation
C([Li])CCC.[CH3:6][O:7][P:8]([CH3:12])(=[O:11])[O:9][CH3:10].C([O:15][C:16](=O)[CH:17]([CH3:23])[CH2:18][CH:19]=[C:20]([CH3:22])[CH3:21])C.C(O)(=O)C>CCCCCC.O1CCCC1>[CH3:6][O:7][P:8]([CH2:12][C:16](=[O:15])[CH:17]([CH3:23])[CH2:18][CH:19]=[C:20]([CH3:22])[CH3:21])(=[O:11])[O:9][CH3:10]

Participants

7

Reactant 4

HCID 176Acetic AcidHCID 12958Dimethyl methylphosphonateHCID 130807222,5-Dimethyl-4-hexenoic Acid Ethyl EsterHCID 178418339Butyllithium

Product 1

HCID 13080723Dimethyl(2-oxo-3,6-dimethyl-5-heptenyl)phosphonateYield 64.4%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Procedure

Under argon at-60° C., 474.7 ml of a 1.61-molar butyllithium solution in hexane is added dropwise to a solution of 59 g of methanephosphonic acid dimethyl ester in 400 ml of absolute tetrahydrofuran. After 15 minutes of agitation, a solution of 34.05 g of the 2,5-dimethyl-4-hexenoic acid ethyl ester described in Example 27(b) in 100 ml of absolute tetrahydrofuran is added dropwise thereto. The reaction mixture is allowed to warm up to room temperature within 4 hours and then stirred for another 3 hours. Thereafter the mixture is combined with 26.5 ml of glacial acetic acid and concentrated under vacuum. The residue is taken up in ether/water, the aqueous phase is combined with solid sodium chloride and extracted with ether. The combined organic phases are dried over magnesium sulfate and concentrated by using a forced-circulation evaporator. The evaporation residue is purified by column chromatography on silica gel with hexane/50-100% ethyl acetate as the eluent, thus obtaining 32 g of the title compound.

Workup

  1. additionis added dropwise
  2. concentrationconcentrated under vacuum
  3. extractionextracted with ether
  4. dry with materialThe combined organic phases are dried over magnesium sulfate
  5. concentrationconcentrated
  6. customa forced-circulation evaporator
  7. customThe evaporation residue is purified by column chromatography on silica gel with hexane/50-100% ethyl acetate as the eluent

Sources & evidence

ORD record
ord-21ce6456dbf04f3a87fbcfc8ce815ac7
Source dataset
uspto-grants-1985_07
Patent number
US04532236

Reaction notes

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