Sodium Methoxide → rac-(E)-3-[2-hydroxy-6-[6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexynyl]phenyl]-2-propenoic acid methyl ester

HRID 1648045Notes

Reaction equation

HRID 1648045 reaction equation
[O:1]1[CH2:6][CH2:5][CH2:4][CH2:3][CH:2]1[O:7][CH2:8][CH2:9][CH2:10][CH2:11][C:12]#[C:13][C:14]1[C:19]2[CH:20]=[CH:21][C:22](=[O:24])[O:23][C:18]=2[CH:17]=[CH:16][CH:15]=1.[CH3:25][O-:26].[Na+]>CO>[CH3:25][O:26][C:22](=[O:24])/[CH:21]=[CH:20]/[C:19]1[C:14]([C:13]#[C:12][CH2:11][CH2:10][CH2:9][CH2:8][O:7][CH:2]2[CH2:3][CH2:4][CH2:5][CH2:6][O:1]2)=[CH:15][CH:16]=[CH:17][C:18]=1[OH:23]

Participants

4

Reactant 2

HCID 10942334Sodium MethoxideHCID 19379916rac-5-[6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexynyl]-2H-1-benzopyran-2-one

Product 1

HCID 67694793rac-(E)-3-[2-hydroxy-6-[6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexynyl]phenyl]-2-propenoic acid methyl esterYield 59.2%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution of 1.09 g (3.3 mmol) of rac-5-[6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexynyl]-2H-1-benzopyran-2-one and 1.8 mL (7.9 mmol) of 25% methanolic sodium methoxide in 5 mL of methanol was stirred and refluxed for 24 hr and then concentrated under reduced pressure. The residue was treated with 1N hydrochloric acid and worked-up with ethyl acetate in the usual manner (the organic extracts were additionally washed with saturated aqueous sodium bicarbonate). The residue was purified by flash chromatography on silica gel, eluting with 2:1 hexane-ether. There was obtained 0.7 g (59%) of rac-(E)-3-[2-hydroxy-6-[6-[(tetrahydro-2H-pyran-2-yl)oxy]-1-hexynyl]phenyl]-2-propenoic acid methyl ester as a yellow oil. Trituration of a sample prepared in this way with hexane gave a colorless solid, mp 66°-67.5° C.

Workup

  1. temperaturerefluxed for 24 hr
  2. concentrationconcentrated under reduced pressure
  3. additionThe residue was treated with 1N hydrochloric acid
  4. washwere additionally washed with saturated aqueous sodium bicarbonate)
  5. customThe residue was purified by flash chromatography on silica gel
  6. washeluting with 2:1 hexane-ether

Sources & evidence

ORD record
ord-8a68ebcb8afe498cb7cc69dd2179f4be
Source dataset
uspto-grants-1995_07
Patent number
US05434186

Reaction notes

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