p-Toluenesulfonic acid → cis-4-Tetrahydropyranyloxy 2-cyclopentenol

HRID 1855944

Reaction equation

HRID 1855944 reaction equation
[CH:1]1([OH:7])[CH2:5][CH:4]([OH:6])[CH:3]=[CH:2]1.C1(C)C=CC(S(O)(=O)=O)=CC=1.[O:19]1[CH:24]=[CH:23][CH2:22][CH2:21][CH2:20]1>C(Cl)Cl.N1C=CC=CC=1.O1CCCC1>[O:19]1[CH2:24][CH2:23][CH2:22][CH2:21][CH:20]1[O:6][C@@H:4]1[CH2:5][C@H:1]([OH:7])[CH:2]=[CH:3]1

Participants

7

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 80803,4-dihydro-2H-pyranHCID 2786004-Cyclopentene-1,3-diol

Product 1

HCID 13623252cis-4-Tetrahydropyranyloxy 2-cyclopentenolYield 71.7%

Reagents, catalysts & solvents 3

HCID 1049PyridineCatalystHCID 8028TetrahydrofuranCatalystHCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 5.0 g of 2-cyclopentene-1,4-diol in 300 ml of methylene chloride was added 5 ml of a solution of p-toluenesulfonic acid in tetrahydrofuran (1 millimole/100 ml). A solution of 4.2 g of 2,3-dihydropyran in 30 ml of methylene chloride was then added dropwise with stirring over a period of 1 hour. After stirring overnight at room temperature, 8 drops of pyridine were added. The methylene chloride was evaporated and the residue was dissolved in diethyl ether, washed with water and dried. The residual obtained by evaporating the solvent was chromatographed on silica gel (200 g) using chloroform as an eluent. First, the diether product flowed out. The subsequent effluent was treated in a customary manner to afford 6.6 g of cis-4-tetrahydropyranyloxy 2-cyclopentenol as colorless oily substance boiling at 84° C. (0.7 mmHg).

Workup

  1. stirringAfter stirring overnight at room temperature
  2. customThe methylene chloride was evaporated
  3. dissolutionthe residue was dissolved in diethyl ether
  4. washwashed with water
  5. customdried
  6. customThe residual obtained
  7. customby evaporating the solvent
  8. customwas chromatographed on silica gel (200 g)
  9. additionThe subsequent effluent was treated in a customary manner

Sources & evidence

ORD record
ord-607412bea2924885b7a1a436db1424ca
Source dataset
uspto-grants-1980_08
Patent number
US04217284

Linked notes

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