3,4-dihydro-2H-pyran → methyl 4-(2-hydroxy-4-(tetrahydro-2H-pyran-2-yloxy)phenyl)-4-oxobutanoate

HRID 1798038Notes

Reaction equation

HRID 1798038 reaction equation
[CH3:1][O:2][C:3](=[O:17])[CH2:4][CH2:5][C:6]([C:8]1[C:13](C)=[CH:12][C:11]([OH:15])=[CH:10][C:9]=1[OH:16])=[O:7].[O:18]1[CH:23]=[CH:22][CH2:21][CH2:20][CH2:19]1>ClCCl>[CH3:1][O:2][C:3](=[O:17])[CH2:4][CH2:5][C:6]([C:8]1[CH:13]=[CH:12][C:11]([O:15][CH:19]2[CH2:20][CH2:21][CH2:22][CH2:23][O:18]2)=[CH:10][C:9]=1[OH:16])=[O:7]

Participants

4

Reactant 2

HCID 80803,4-dihydro-2H-pyranHCID 582926554-(2,4-Dihydroxy-6-methyl-phenyl)-4-oxo-butyric acid methyl ester

Product 1

HCID 59525512methyl 4-(2-hydroxy-4-(tetrahydro-2H-pyran-2-yloxy)phenyl)-4-oxobutanoateYield 84.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a mixture of 4-(2,4-dihydroxy-6-methyl-phenyl)-4-oxo-butyric acid methyl ester (1.0 g, 4.20 mmol) in dichloromethane (50 mL) was added 3,4-dihydro-2H-pyran (0.38 mL, 8.40 mmol) and pyridium p-toluenesulfonic acid (0.010 g) at room temperature. The resulting mixture was stirred at room temperature for 16 hours then concentrated in vacuo. The residue was purified by silica gel flash column chromatography to give 4-[2-hydroxy-4-(tetrahydro-pyran-2-yloxy)-phenyl]-4-oxo-butyric acid methyl ester (1.1 g, 81%). 1HNMR (400 MHz, CDCl3): 12.40 (s, 1H), 6.95 (s, 1H), 6.90 (s, 1H), 5.90 (br s, 1H), 3.27 (t, J=7.8 Hz, 2H), 2.78 (t, J=7.8 Hz, 2H), 2.30 (s, 3H).

Workup

  1. concentrationthen concentrated in vacuo
  2. customThe residue was purified by silica gel flash column chromatography

Sources & evidence

ORD record
ord-cf19c206a4094127922e92424e827f57
Source dataset
uspto-grants-2013_01
Patent number
US08343944B2

Reaction notes

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