3,4-dihydro-2H-pyran → 4-(Tetrahydro-pyran-2-yloxy)-cyclopent-2-enone

HRID 232229

Reaction equation

HRID 232229 reaction equation
[OH:1][CH:2]1[CH2:6][C:5](=[O:7])[CH:4]=[CH:3]1.[O:8]1[CH:13]=[CH:12][CH2:11][CH2:10][CH2:9]1.C(=O)([O-])O.[Na+]>ClCCl.C1(C)C=CC(S(O)(=O)=O)=CC=1>[O:8]1[CH2:13][CH2:12][CH2:11][CH2:10][CH:9]1[O:7][CH:5]1[CH2:6][C:2](=[O:1])[CH:3]=[CH:4]1

Participants

6

Reactant 3

HCID 80803,4-dihydro-2H-pyranHCID 516892Sodium BicarbonateHCID 41691604-Hydroxycyclopent-2-en-1-one

Product 1

HCID 128380104-(Tetrahydro-pyran-2-yloxy)-cyclopent-2-enoneYield 93.7%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 6344DichloromethaneSolvent

Procedure

In 300 ml of dichloromethane was dissolved 10 g of 4-hydroxy-2-cyclopentenone. To the solution were added 25.7 g of dihydropyran and 0.5 g of p-toluenesulfonic acid, and the mixture was stirred at room temperature for 45 minutes. The reaction solution was poured into an aqueous solution of sodium hydrogencarbonate. The organic layer was separated. The aqueous layer was further extracted with dichloromethane. The organic layers were combined, washed with a saturated aqueous saline solution, then dried (Na2SO4). The solvent was evaporated off, and the residue was subjected to a silica gel column chromatography, followed by elution with hexane--ethyl acetate (7:3) to give 17.4 g of 4-(2-tetrahydropyranyl)oxy-2-cyclopentenone as an oily product.

Workup

  1. customThe organic layer was separated
  2. extractionThe aqueous layer was further extracted with dichloromethane
  3. washwashed with a saturated aqueous saline solution
  4. dry with materialdried (Na2SO4)
  5. customThe solvent was evaporated off
  6. washfollowed by elution with hexane--ethyl acetate (7:3)

Sources & evidence

ORD record
ord-71408589cb3444fbb85df478f0348ffe
Source dataset
uspto-grants-1989_07
Patent number
US04851422

Linked notes

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