4-[[2-(1,1-Dimethylethoxy)-2-oxoethyl]oxy]-alpha-methyl-benzenepropanoic acid, methyl ester → 4-[[2-(1,1-Dimethylethoxy)-2-oxoethyl]oxy]-alpha-methyl-benzenepropanoic acid
Reaction equation
[CH3:1][C:2]([CH3:22])([O:4][C:5](=[O:21])[CH2:6][O:7][C:8]1[CH:13]=[CH:12][C:11]([CH2:14][CH:15]([CH3:20])[C:16]([O:18]C)=[O:17])=[CH:10][CH:9]=1)[CH3:3]>C(OCC)C.P([O-])([O-])([O-])=O>[CH3:22][C:2]([CH3:3])([O:4][C:5](=[O:21])[CH2:6][O:7][C:8]1[CH:13]=[CH:12][C:11]([CH2:14][CH:15]([CH3:20])[C:16]([OH:18])=[O:17])=[CH:10][CH:9]=1)[CH3:1]Participants
4
Reactant 1
Product 1
Reagents, catalysts & solvents 2
Procedure
Dissolve (+)-4-[[2-(1,1-dimethylethoxy)-2-oxoethyl]oxy]-alpha-methyl-benzenepropanoic acid, methyl ester (5.74 g, 18.6 mmol) in ethyl ether and adsorb onto silica gel (18 g). Evaporate the solvent in vacuo to leave a white powder. Suspend the powder in pH 7 phosphate buffer (600 mL of a 0.1M solution). Add lipase P-30 (5.74 g) and stir for 16 hours. Filter and extract with ethyl ether (3×400 mL). Dry (MgSO4), evaporate the solvent in vacuo and purify by flash chromatography (5→10% methanol/chloroform) to give the title compound (5.09 g, 98% ee after reesterification with diazomethane); [α]d 20 =+18.9° (C=0.97, CHCl3).
Workup
- customEvaporate the solvent in vacuo
- customto leave a white powder
- additionAdd lipase P-30 (5.74 g)
- filtrationFilter
- extractionextract with ethyl ether (3×400 mL)
- dry with materialDry (MgSO4)
- customevaporate the solvent in vacuo
- custompurify by flash chromatography (5→10% methanol/chloroform)
Sources & evidence
- ORD record
- ord-0a447fe48068438388e9bd6053bd951f
- Source dataset
- uspto-grants-1993_05
- Patent number
- US05208240
Reaction notes
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