p-Toluenesulfonic acid → AG-G-89175

HRID 1654186Notes

Reaction equation

HRID 1654186 reaction equation
[C:1]([O:6][CH2:7][CH3:8])(=[O:5])[C@H:2]([CH3:4])[OH:3].C1(C)C=CC(S(O)(=O)=O)=CC=1.[O:20]1[CH:25]=[CH:24][CH2:23][CH2:22][CH2:21]1.C(=O)([O-])O.[Na+]>ClCCl>[O:20]1[CH2:25][CH2:24][CH2:23][CH2:22][CH:21]1[O:3][C@@H:2]([CH3:4])[C:1]([O:6][CH2:7][CH3:8])=[O:5]

Participants

6

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 80803,4-dihydro-2H-pyranHCID 92831(L)-ethyl lactateHCID 516892Sodium Bicarbonate

Product 1

HCID 10397939AG-G-89175Yield 100.6%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

In dichloromethane (200 ml) was dissolved (S)-(-)-ethyl lactate (35.4 g), to which was added, under ice-cooling, p-toluenesulfonic acid.hydrate (570 mg). To the mixture was added dropwise 3,4-dihyro-2H-pyran (30.2 g), taking 30 minutes, followed by stirring for one hour under ice-cooling. To the reaction mixture was added a 5% aqueous solution of sodium hydrogen carbonate (50 ml), which was vigorously stirred, then the organic layer was separated. The organic layer was further washed with a 5% aqueous solution of sodium hydrogen carbonate and dried over anhydrous magnesium sulfate, then the solvent was distilled off under reduced pressure to afford ethyl(2S)-2-(3,4,5,6-tetrahydro-2H-pyran-2-yloxy)propionate (61 g) as a pale yellow oily product.

Workup

  1. additionto which was added, under ice-
  2. temperaturecooling
  3. temperaturecooling
  4. stirringwas vigorously stirred
  5. customthe organic layer was separated
  6. washThe organic layer was further washed with a 5% aqueous solution of sodium hydrogen carbonate
  7. dry with materialdried over anhydrous magnesium sulfate
  8. distillationthe solvent was distilled off under reduced pressure

Sources & evidence

ORD record
ord-f84b4e21dbd642ed98b3faa8b7e3b0bd
Source dataset
uspto-grants-1995_04
Patent number
US05405861

Reaction notes

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