Carbon tetrabromide → 6-(4-bromo-3-methyl-but-2-enyl)-7-hydroxy-5-methoxy-4-methyl-3H-isobenzofuran-1-one

HRID 32949

Reaction equation

HRID 32949 reaction equation
C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[OH:20][C:21]1[C:22]([CH2:34][CH:35]=[C:36]([CH3:39])[CH2:37]O)=[C:23]([O:32][CH3:33])[C:24]([CH3:31])=[C:25]2[C:29]=1[C:28](=[O:30])[O:27][CH2:26]2.C(Br)(Br)(Br)[Br:41]>ClCCl>[Br:41][CH2:37][C:36]([CH3:39])=[CH:35][CH2:34][C:22]1[C:21]([OH:20])=[C:29]2[C:25]([CH2:26][O:27][C:28]2=[O:30])=[C:24]([CH3:31])[C:23]=1[O:32][CH3:33]

Participants

5

Reactant 3

HCID 11205Carbon tetrabromide2×HCID 11776TriphenylphosphineHCID 30062907-hydroxy-6-(4-hydroxy-3-methyl-but-2-enyl)-5-methoxy-4-methyl-3H-isobenzofuran-1-one

Product 1

HCID 670104826-(4-bromo-3-methyl-but-2-enyl)-7-hydroxy-5-methoxy-4-methyl-3H-isobenzofuran-1-oneYield 42.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Polymer-supported triphenylphosphine (3 mmol/g, 0.5 g) was soaked in dichloromethane (10 mL) for 1 hour 7-Hydroxy-6-(4-hydroxy-3-methyl-but-2-enyl)-5-methoxy-4-methyl-3H-isobenzofuran-1-one 1A (100 mg, 0.36 mmol) and carbon tetrabromide (143 mg, 0.43 mmol) were sequentially added and the mixture was shaken for 1 hour at room temperature. More carbon tetrabromide (143 mg, 0.43 mmol) was added and the mixture was shaken further for 1 hour. The mixture was filtered and the filtrate was concentrated. The residue was chromatographed on silica gel (0% to 60% ethyl acetate/hexanes) to afford 6-(4-bromo-3-methyl-but-2-enyl)-7-hydroxy-5-methoxy-4-methyl-3H-isobenzofuran-1-one 3B as an oil (52 mg, 42%); 1H NMR (300 MHz, CDCl3) δ 1.95 (s, 3H), 2.16 (s, 3H), 3.44 (d, J=7.2 Hz, 2H), 3.78 (s, 3H), 3.98 (s, 2H), 5.21 (s, 2H), 5.68 (t, J=7.2 Hz, 1H), 7.71 (brs, 1H) ppm.

Workup

  1. stirringthe mixture was shaken further for 1 hour
  2. filtrationThe mixture was filtered
  3. concentrationthe filtrate was concentrated
  4. customThe residue was chromatographed on silica gel (0% to 60% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-218a8498aaad403ab913cd2b3c09f426
Source dataset
uspto-grants-2008_09
Patent number
US07427636B2

Linked notes

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