Benzoic Acid → ethyl mandelate, (S)-

HRID 2166212Notes

Reaction equation

HRID 2166212 reaction equation
[BH4-].[Na+].C(O)(=O)C1C=CC=CC=1.C([C@@H]([C@H](C(OCC)=O)O)O)(OCC)=O.[C:26]1([C:32](=[O:38])[C:33]([O:35][CH2:36][CH3:37])=[O:34])[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1>C1COCC1>[OH:38][C@@H:32]([C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)[C:33]([O:35][CH2:36][CH3:37])=[O:34]

Participants

6

Reactant 4

HCID 243Benzoic AcidHCID 15349Ethyl benzoylformateHCID 4311764Sodium borohydrideHCID 6993580Diethyl tartrate

Product 1

HCID 6951557ethyl mandelate, (S)-Yield 85.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

A dispersion of 0.43 g (11.3 mmol) of sodium borohydride in THF (20 ml) was cooled in a cryostat at -20° C., 1.38 g (11.3 mmol) of benzoic acid was added with stirring, and the mixture was stirred for two to three minutes. A solution of diethyl L-(+)-tartrate in THF (10 ml) was then added, the mixture was stirred for five minutes, a solution of 5 g (2.8 mmol) of ethyl phenyl-glyoxylate in THF (2 ml) was further added over a period of one to two minutes, and stirring was continued for one hour. The reaction mixgture was treated in the same manner as described in Example 1, giving 0.43 g of ethyl (S)-(+)-2-hydroxy-2-phenylacetate, having specific rotation [α]D18 of +17.6° (cl. 18, CHCl3). The synthesis yield was 85% and the optical yield was 15% e.e. (see Reference 7).

Workup

  1. stirringthe mixture was stirred for two to three minutes
  2. stirringthe mixture was stirred for five minutes
  3. stirringstirring
  4. additionThe reaction mixgture was treated in the same manner

Sources & evidence

ORD record
ord-5da58fb643ad46da9ccf53bde2aec21b
Source dataset
uspto-grants-1990_07
Patent number
US04943652

Reaction notes

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