3,4-dihydro-2H-pyran → HCID 58292840, compound

HRID 1798261Notes

Reaction equation

HRID 1798261 reaction equation
[Br:1][C:2]1[CH:9]=[C:8]([OH:10])[CH:7]=[C:6]([OH:11])[C:3]=1[CH:4]=[O:5].[CH2:12]1[CH2:17][O:16][CH:15]=[CH:14][CH2:13]1>ClCCl.CC1C=CC(S([O-])(=O)=O)=CC=1.C1C=C[NH+]=CC=1>[Br:1][C:2]1[CH:9]=[C:8]([O:10][CH:15]2[CH2:14][CH2:13][CH2:12][CH2:17][O:16]2)[CH:7]=[C:6]([OH:11])[C:3]=1[CH:4]=[O:5]

Participants

5

Reactant 2

HCID 80803,4-dihydro-2H-pyranHCID 58292554HCID 58292554, compound

Product 1

HCID 58292840HCID 58292840, compoundYield 92%

Reagents, catalysts & solvents 2

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

Procedure

A solution of 2-bromo-4,6-dihydroxy-benzaldehyde (4.69 g, 21.7 mmol) in dichloromethane (100 mL) was treated with DHP (3.94 mL, 43.4 mmol) and PPTS (200 mg) at room temperature for 1 h. The reaction mixture was concentrated to dryness. The residue purified by flash column chromatography (silica, hexanes/ethyl acetate=4:1) to give the title compound (5.96 g, 92%) as a colorless oil. 1H NMR (300 MHz, CDCl3) δ 12.2 (s, 1H), 10.1 (s, 1H), 6.88 (d, J=2.1 Hz, 1H), 6.58 (d, J=2.1 Hz, 1H), 5.56 (s, 1H), 3.84-3.81 (m, 1H), 3.68-3.62 (m, 1H), 1.96-1.54 (m, 6H).

Workup

  1. concentrationThe reaction mixture was concentrated to dryness
  2. customThe residue purified by flash column chromatography (silica, hexanes/ethyl acetate=4:1)

Sources & evidence

ORD record
ord-f5d2dc7ff7e84a47bb91fad7bec0f6c2
Source dataset
uspto-grants-2013_01
Patent number
US08343944B2

Reaction notes

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