3,4-dihydro-2H-pyran → HCID 22026141, compound

HRID 1793213Notes

Reaction equation

HRID 1793213 reaction equation
[OH:1][C:2]1[C:9]([CH3:10])=[C:8]([CH3:11])[C:7]([OH:12])=[CH:6][C:3]=1[CH:4]=[O:5].[O:13]1[CH:18]=[CH:17][CH2:16][CH2:15][CH2:14]1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>ClCCl>[OH:1][C:2]1[C:9]([CH3:10])=[C:8]([CH3:11])[C:7]([O:12][CH:14]2[CH2:15][CH2:16][CH2:17][CH2:18][O:13]2)=[CH:6][C:3]=1[CH:4]=[O:5]

Participants

5

Reactant 3

HCID 80803,4-dihydro-2H-pyranHCID 521998p-Toluenesulfonic acid monohydrateHCID 22026144HCID 22026144, compound

Product 1

HCID 22026141HCID 22026141, compoundYield 49.8%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

2,5-Dihydroxy-3,4-dimethyl-benzaldehyde (2.0 g) was dissolved in dichloromethane (50 mL) and 3,4-dihydro-2H-pyran (1.5 g) was added followed by addition of p-toluenesulfonic acid monohydrate (200 mg). The solution was stirred at room temperature for 1 hour and quenched by adding sodium bicarbonate solution (1 mL). Then the dichloromethane solution was dried over MgSO4 and concentrated. The residue was purified by silica gel column eluting with hexane and ethyl acetate (8:2) to give 1.5 g of 2-hydroxy-3,4-dimethyl-5-(tetrahydro-pyran-2-yloxy)-benzaldehyde product.

Workup

  1. customquenched
  2. additionby adding sodium bicarbonate solution (1 mL)
  3. dry with materialThen the dichloromethane solution was dried over MgSO4
  4. concentrationconcentrated
  5. customThe residue was purified by silica gel column
  6. washeluting with hexane and ethyl acetate (8:2)

Sources & evidence

ORD record
ord-7de22d0f2eb54aa7921a13c19744900f
Source dataset
uspto-grants-2006_07
Patent number
US07078541B2

Reaction notes

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