Water → 3-(1,1-Dimethylheptyl)-1,9-dihydroxy-6H-dibenzo[b,d]pyran-6-one

HRID 18624Notes

Reaction equation

HRID 18624 reaction equation
[CH3:1][C:2]([C:10]1[CH:11]=[C:12]([OH:27])[C:13]2[C:18]3[CH:19]=[C:20]([O:23]C)[CH:21]=[CH:22][C:17]=3[C:16](=[O:25])[O:15][C:14]=2[CH:26]=1)([CH3:9])[CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH3:8].B(Br)(Br)Br.O>ClCCl>[CH3:9][C:2]([C:10]1[CH:11]=[C:12]([OH:27])[C:13]2[C:18]3[CH:19]=[C:20]([OH:23])[CH:21]=[CH:22][C:17]=3[C:16](=[O:25])[O:15][C:14]=2[CH:26]=1)([CH3:1])[CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH3:8]

Participants

5

Reactant 3

HCID 962WaterHCID 25134Boron tribromideHCID 11268660335371-36-3

Product 1

HCID 99504863-(1,1-Dimethylheptyl)-1,9-dihydroxy-6H-dibenzo[b,d]pyran-6-oneYield 78.4%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

3-(1,1-Dimethylheptyl)-1-hydroxy-9-methoxy-6H-dibenzo[b,d]pyran-6-one (4b) (200 mg, 0.54 mmol) was dissolved in 12 mL of dry dichloromethane, 2 mL of a 1M solution of boron tribromide in dichloromethane (2 mmol) was added and the resulting mixture was stirred at room temperature for 3 days. Water was added and the mixture was extracted with diethyl ether. The organic extract was dried and rotary evaporated. The residue was chromatographed on silica gel (50% ethyl ether-petroleum ether) to afford 150 mg of a flaky off-white foam: m.p. 103-108° C.; Rf; 0.28 (50% diethyl ether-petroleum ether); 1H NMR δ 8.60 (m, 1H), 8.35 (d, 1H), 7.05 (d, 1H), 6.90 (s, 1H), 6.73 (s, 1H), 6.10 (br s, 2H), 1.70-0.98 (series of m, 10H), 1.27 (s, 6H), 0.82 (t, J=6.6 Hz, 3H); Anal. calcd. for C23H28O4 74.55% C, 7.39% H. Found 72.70% C, 7.25% H.

Workup

  1. extractionthe mixture was extracted with diethyl ether
  2. extractionThe organic extract
  3. customwas dried
  4. customThe residue was chromatographed on silica gel (50% ethyl ether-petroleum ether)

Sources & evidence

ORD record
ord-13371113ae0c4d2b90061ee1c731c7f7
Source dataset
uspto-grants-2010_06
Patent number
US07741365B2

Reaction notes

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