Propargyl alcohol → Tetrahydro-2-(2-propynyloxy)-2H-pyran

HRID 2255025Notes

Reaction equation

HRID 2255025 reaction equation
[CH2:1]([OH:4])[C:2]#[CH:3].[O:5]1[CH:10]=[CH:9][CH2:8][CH2:7][CH2:6]1>C(Cl)Cl.C1(C)C=CC(S(O)(=O)=O)=CC=1>[CH2:1]([O:4][CH:6]1[CH2:7][CH2:8][CH2:9][CH2:10][O:5]1)[C:2]#[CH:3]

Participants

5

Reactant 2

HCID 7859Propargyl alcoholHCID 80803,4-dihydro-2H-pyran

Product 1

HCID 98609Tetrahydro-2-(2-propynyloxy)-2H-pyranYield 97%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
20 °C

Procedure

To a stirred solution of propargyl alcohol (5g, 90 mmol) and dihydropyran (37.5 g, 0.44 mol, 5 equiv) in CH2Cl2 (300 ML), was added p-toluenesufonic acid (30 mg). The mixture was stirred at 20° C. for 1.5 hours. The solvent was removed by rotary evaporation. The residue was taken up in ether (150 mL) and washed with aqueous saturated NaHCO3 (120 mL), saturated NaCl (120 mL), water (200 mL). The organic layer was dried (MgSO4) and concentrated to yield a yellow oil. Purification by distillation under reduced pressure gave Tetrahydro-2-(2-propynyloxy)-2H-pyran (47) (12 g, 97%) as a colorless oil: bp: (40° C., 0.05 mm Hg). ##STR20##

Workup

  1. customThe solvent was removed by rotary evaporation
  2. washwashed with aqueous saturated NaHCO3 (120 mL), saturated NaCl (120 mL), water (200 mL)
  3. dry with materialThe organic layer was dried (MgSO4)
  4. concentrationconcentrated
  5. customto yield a yellow oil
  6. customPurification
  7. distillationby distillation under reduced pressure

Sources & evidence

ORD record
ord-a1e9ad9f01434b4591fbb25bbe702b9b
Source dataset
uspto-grants-1993_08
Patent number
US05238832

Reaction notes

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