Tetrahydrofuran → 5-Methoxy-3-Chromanone

HRID 2292152Notes

Reaction equation

HRID 2292152 reaction equation
[H-].[Na+].Br[C@H:4]1[C@H:9](O)[C:8]2[C:11]([O:15][CH3:16])=[CH:12][CH:13]=[CH:14][C:7]=2[O:6][CH2:5]1.[O:17]1CCCC1>>[CH3:16][O:15][C:11]1[C:8]2[CH2:9][C:4](=[O:17])[CH2:5][O:6][C:7]=2[CH:14]=[CH:13][CH:12]=1

Participants

4

Reactant 3

HCID 8028Tetrahydrofuran2×HCID 24758Sodium hydrideHCID 15097552trans-3-bromo-4-hydroxy-5-methoxy-3,4-dihydro-2H-[1]benzopyran

Product 1

HCID 117690965-Methoxy-3-Chromanone

Procedure

To a suspension of 5.0 g sodium hydride in 100 ml of dry tetrahydrofuran is added with stirring a solution of 13 g of trans-3-bromo-4-hydroxy-5-methoxy-3,4-dihydro-2H-[1]-benzopyran in 150 ml of dry tetrahydrofuran in a dropwise fashion. After 30 minutes stirring at room temperature, the reaction mixture is filtered through filter-cel and the solvent is removed in vacuo. The residue is dissolved in 150 ml of toluene, 1.0 g of anhydrous zinc iodide is added and the mixture is refluxed for 15 minutes. The reaction mixture is filtered through 120 g of silica gel with methylene chloride as the eluent to afford 5-methoxy-3,4-dihydro-2H-[1]-benzopyran-3-one (5-methoxychroman-3-one) as an oil.

Workup

  1. additionis added
  2. filtrationthe reaction mixture is filtered
  3. filtrationthrough filter-cel
  4. customthe solvent is removed in vacuo
  5. dissolutionThe residue is dissolved in 150 ml of toluene
  6. addition1.0 g of anhydrous zinc iodide is added
  7. temperaturethe mixture is refluxed for 15 minutes
  8. filtrationThe reaction mixture is filtered through 120 g of silica gel with methylene chloride as the eluent

Sources & evidence

ORD record
ord-2dd68b2405db4976903717b217e918e8
Source dataset
uspto-grants-1989_01
Patent number
US04801605

Reaction notes

Loading…