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

HRID 2210081Notes

Reaction equation

HRID 2210081 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 (preceding example) 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-e8f820f61aca424abdef26fc015576bd
Source dataset
uspto-grants-1995_10
Patent number
US05457124

Reaction notes

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