Phosphorus oxychloride → 3,4-Dihydro-4,4-dimethyl-2H-pyran-2-one

HRID 1732207Notes

Reaction equation

HRID 1732207 reaction equation
[CH3:1][C:2]([CH3:12])([CH2:9][CH:10]=O)[CH2:3][C:4]([O:6]CC)=[O:5].P(Cl)(Cl)(Cl)=O>C1(C)C=CC=CC=1.CCOCC>[CH3:12][C:2]1([CH3:1])[CH:9]=[CH:10][O:6][C:4](=[O:5])[CH2:3]1

Participants

5

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 13050815Ethyl 4-formyl-3,3-dimethylbutanoate

Product 1

HCID 30186853,4-Dihydro-4,4-dimethyl-2H-pyran-2-oneYield 40.1%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 3283Diethyl EtherSolvent

Procedure

A solution of 11.16 g (0.065 mole) of ethyl 3,3-dimethyl-5-oxopentanoate and 11.2 g (0.073 mole) of phosphoryl chloride in 90 ml of toluene was heated under reflux for 14 hours. The mixture was diluted with ether, washed with an aqueous solution of sodium bicarbonate, dried over anhydrous magnesium sulfate, filtered, and the filtrate concentrated to give, after distillation, 3.29 g (40% yield) of 3,4-dihydro-4,4-dimethyl-2H-pyran-2-one, bp 105°-110° C./2670 Pa (20 mm Hg).

Workup

  1. temperatureunder reflux for 14 hours
  2. washwashed with an aqueous solution of sodium bicarbonate
  3. dry with materialdried over anhydrous magnesium sulfate
  4. filtrationfiltered
  5. concentrationthe filtrate concentrated
  6. customto give

Sources & evidence

ORD record
ord-9d8f64d97f0b4ae2bb987cd71ecc228b
Source dataset
uspto-grants-1980_12
Patent number
US04237058

Reaction notes

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