3,4-dihydro-2H-pyran → 2-(5-Bromopentyloxy)tetrahydro-2H-pyran

HRID 127800Notes

Reaction equation

HRID 127800 reaction equation
[Br:1][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][OH:7].[O:8]1[CH:13]=[CH:12][CH2:11][CH2:10][CH2:9]1>P(Cl)(Cl)(Cl)=O.C(OCC)C>[Br:1][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][O:7][CH:9]1[CH2:10][CH2:11][CH2:12][CH2:13][O:8]1

Participants

5

Reactant 2

HCID 80803,4-dihydro-2H-pyranHCID 1187091-Pentanol, 5-bromo-

Product 1

HCID 27869332-(5-Bromopentyloxy)tetrahydro-2H-pyran

Reagents, catalysts & solvents 2

HCID 24813Phosphorus oxychlorideCatalystHCID 3283Diethyl EtherSolvent

Procedure

To 36 g of 5-bromopentan-1-ol were added 24.72 ml of 2,3-dihydropyran and 3 drops of phosphorus oxychloride under cooling in an ice bath, and the mixture was stirred overnight at room temperature. The reaction mixture was diluted with diethyl ether, washed with 5% aqueous potassium hydroxide, water, a saturated aqueous solution of sodium chloride, dried over magnesium sulphate and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel using a mixture of ethyl acetate and hexane (1:19) as eluent to give 49.5 g of the subtitle compound having the following physical characteristics:

Workup

  1. temperatureunder cooling in an ice bath
  2. washwashed with 5% aqueous potassium hydroxide, water
  3. dry with materiala saturated aqueous solution of sodium chloride, dried over magnesium sulphate
  4. concentrationconcentrated under reduced pressure
  5. customThe residue was purified by column chromatography on silica gel using
  6. additiona mixture of ethyl acetate and hexane (1:19) as eluent

Sources & evidence

ORD record
ord-a7b12ef579b64c6491bfc0e7afa3bd18
Source dataset
uspto-grants-1981_03
Patent number
US04256757

Reaction notes

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