p-Toluenesulfonic acid → (R)-2-(tetrahydro-pyran-2-yloxy)-propionic acid methyl ester
Reaction equation
[C:1]([O:6][CH3:7])(=[O:5])[C@@H:2]([CH3:4])[OH:3].C1(C)C=CC(S(O)(=O)=O)=CC=1.[O:19]1[CH:24]=[CH:23][CH2:22][CH2:21][CH2:20]1.C(=O)([O-])O.[Na+]>ClCCl>[O:19]1[CH2:24][CH2:23][CH2:22][CH2:21][CH:20]1[O:3][C@H:2]([CH3:4])[C:1]([O:6][CH3:7])=[O:5]Participants
Procedure
Methyl (R)-(+)-lactate (25.0 g) was dissolved in dichloromethane (250 ml), to which was added, under ice-cooling, p-toluenesulfonic acid.hydrate (456 mg). To the mixture was then added dropwise 3,4-dihydro-2H-pyran (24.2 g) during 30 minutes, which was stirred for one hour under ice-cooling. To the reaction mixture was added a 5% aqueous solution of sodium hydrogen carbonate (50 ml), and the mixture was stirred vigorously, followed by separating the organic layer. The organic layer was further washed with a 5% aqueous solution of sodium hydrogen carbonate, which was dried over anhydrous magnesium sulfate, followed by distilling off the solvent under reduced pressure to leave methyl (2R)-2-(3,4,5,6-tetrahydro-2H-pyran-2-yloxy)propionate (42.7 g) as a pale yellow oily product.
Workup
- additionwas added, under ice-
- temperaturecooling
- temperaturecooling
- stirringthe mixture was stirred vigorously
- customby separating the organic layer
- washThe organic layer was further washed with a 5% aqueous solution of sodium hydrogen carbonate, which
- dry with materialwas dried over anhydrous magnesium sulfate
- distillationby distilling off the solvent under reduced pressure
Sources & evidence
- ORD record
- ord-7a16b6ea7d494e3898485df5ff9ac16c
- Source dataset
- uspto-grants-1995_04
- Patent number
- US05405861
Reaction notes
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