반응 #1741376

반응 방정식

3,4-dihydro-2H-pyran

sodium hydrogen carbonate

p-toluenesulfonic acid

Methyl (R)-(+)-lactate

→

methyl (2R)-2-(3,4,5,6-tetrahydro-2H-pyran-2-yloxy)propionate

수율 94.5%

용매

dichloromethane

반응 조건

후처리

1. 1
   workup.ADDITIONwas added, under ice-
2. 2
   온도cooling
3. 3
   온도cooling
4. 4
   workup.STIRRINGthe mixture was stirred vigorously
5. 5
   기타by separating the organic layer
6. 6
   세척The organic layer was further washed with a 5% aqueous solution of sodium hydrogen carbonate, which
7. 7
   건조was dried over anhydrous magnesium sulfate
8. 8
   workup.DISTILLATIONby distilling off the solvent under reduced pressure

실험 절차

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.

출처