p-Toluenesulfonic acid → methyl (2R)-2-hydroxy-3-phenylpropanoate

HRID 373654Notes

Reaction equation

HRID 373654 reaction equation
[OH:1][C@H:2]([CH2:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)[C:3]([OH:5])=[O:4].[C:13]1(C)C=CC(S(O)(=O)=O)=CC=1>CO>[OH:1][C@H:2]([CH2:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)[C:3]([O:5][CH3:13])=[O:4]

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 643327(R)-3-phenyllactic acid

Product 1

HCID 10986876methyl (2R)-2-hydroxy-3-phenylpropanoateYield 407%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Following the procedure of Cohen (J. Am. Chem. Soc., 1964, 86, 5326), the resultant compound from Example 89 (8.6 g, 52 mmol) was dissolved in dry methanol (250 ml). p-Toluenesulfonic acid (2 g, 10.5 mmol) was added and the solution was refluxed for 2 h. The cooled solution was concentrated in vacuo and the residue was dissolved in ether (400 ml). The ether solution was washed with saturated aqueous NaHCO3 (3×50 ml), water (2×50 ml), 0.1N H2SO4 (1×50 ml), water (1×50 ml), dried over Na2SO4, and concentrated in vacuo to afford a colorless solid. The solid was recrystallized from hexane to provide the title compound as colorless needles (7.7 g, 83%); mp=46°-47° C.

Workup

  1. temperaturethe solution was refluxed for 2 h
  2. concentrationThe cooled solution was concentrated in vacuo
  3. dissolutionthe residue was dissolved in ether (400 ml)
  4. washThe ether solution was washed with saturated aqueous NaHCO3 (3×50 ml), water (2×50 ml), 0.1N H2SO4 (1×50 ml), water (1×50 ml)
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated in vacuo
  7. customto afford a colorless solid
  8. customThe solid was recrystallized from hexane

Sources & evidence

ORD record
ord-cc462f2da86b4ab7a825298237e97d91
Source dataset
uspto-grants-1992_11
Patent number
US05164388

Reaction notes

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