3,4-dihydro-2H-pyran → HCID 10823699, compound

HRID 1798140Notes

Reaction equation

HRID 1798140 reaction equation
[OH:1][C:2]1[CH:9]=[C:8]([OH:10])[CH:7]=[C:6]([CH3:11])[C:3]=1[CH:4]=[O:5].[O:12]1[CH:17]=[CH:16][CH2:15][CH2:14][CH2:13]1>C(Cl)Cl.O.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>[OH:1][C:2]1[CH:9]=[C:8]([O:10][CH:13]2[CH2:14][CH2:15][CH2:16][CH2:17][O:12]2)[CH:7]=[C:6]([CH3:11])[C:3]=1[CH:4]=[O:5]

Participants

6

Reactant 2

HCID 80803,4-dihydro-2H-pyranHCID 251690o-Orsellinaldehyde

Product 1

HCID 10823699HCID 10823699, compoundYield 77.9%

Reagents, catalysts & solvents 3

HCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)CatalystHCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

A light yellow suspension of 2,4-dihydroxy-6-methyl-benzaldehyde (4.90 g, 24.98 mmol) in DCM (400 mL) was treated with 3,4-dihydro-2H-pyran (3.5 mL, 38.61 mmol) followed by pyridinium-p-toluenesulfonate (0.20 g, 0.80 mmol). The suspension slowly cleared to a yellow solution. The solution was stirred at rt overnight then diluted with water and washed with saturated NaHCO3. The organic layer was dried (Na2SO4), filtered and concentrated to a yellow oil. The residue was purified by column chromatography (SiO2, EtOAc/hexanes; 1:9) to afford 2-hydroxy-6-methyl-4-(tetrahydro-pyran-2-yloxy)-benzaldehyde (4.60 g, 70%), as a light yellow liquid. 1H NMR (400 MHz, CDCl3) δ 12.33 (s, 1H), 10.09 (s, 1H), 6.45 (d, J=2 Hz, 1H), 6.08 (d, J=2 Hz, 1H), 5.49-5.40 (m, 1H), 3.90-3.80 (m, 1H), 3.65-3.60 (m, 1H), 2.52 (s, 3H), 2.10-1.40 (m, 6H).

Workup

  1. washwashed with saturated NaHCO3
  2. dry with materialThe organic layer was dried (Na2SO4)
  3. filtrationfiltered
  4. concentrationconcentrated to a yellow oil
  5. customThe residue was purified by column chromatography (SiO2, EtOAc/hexanes; 1:9)

Sources & evidence

ORD record
ord-1031df495cd9484a9a425f7c265bfcc4
Source dataset
uspto-grants-2013_01
Patent number
US08343944B2

Reaction notes

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