HCID 22858886, compound → HCID 10798722, compound

HRID 2396430Notes

Reaction equation

HRID 2396430 reaction equation
[C:1]([NH:4][C@:5]([CH3:15])([C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH2:6][CH:7]([CH3:9])[CH3:8])(=[O:3])[CH3:2]>P([O-])([O-])([O-])=O.[Na+].[Na+].[Na+]>[C:1]([NH:4][C@@:5]([CH3:15])([C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH2:6][CH:7]([CH3:9])[CH3:8])(=[O:3])[CH3:2]

Participants

3

Reactant 1

HCID 22858886HCID 22858886, compound

Product 1

HCID 10798722HCID 10798722, compoundYield 48%

Reagents, catalysts & solvents 1

HCID 24243Trisodium PhosphateSolvent

Procedure

To a solution of ethyl N-acetyl-(±)-α-methylleucinate (250.0 mg, 1.16 mmol) in 70 mL of 50 mM sodium phosphate buffer pH 7.5 is added carboxypeptidase Y from Bakers Yeast (10.4 mg of protein). After 120 h, 50% conversion is observed by HPLC (C18 column, 210 nm detection, amido acid tR =8.1 rain and amido ester tR =10.7 min). The reaction is extracted with 3×25 mL chloroform. The combined extracts are dried with magnesium sulfate and concentrated in vacuo to yield ethyl (R)-N-acetyl-α-methylleucinate (120 mg, 0.557 mmol, 48%). A portion of this (R)-α-methyl amido ester (70 mg, 0.325 mmol) is refluxed in 50 mL 6N HCl for 2 h then concentrated in vacuo to afford (R)-α-methylleucine hydrochloride (70 mg). The enantiomeric excess of the amino acid is determined by HPLC analysis ((D)-Penicillinamine column from Phenomonex, detection 254 nm, (S)-enantiomer tR =4.6 min and (R)-enantiomer tR =7.4 min) to be >98% (R)-enantiomer.

Workup

  1. extractionThe reaction is extracted with 3×25 mL chloroform
  2. dry with materialThe combined extracts are dried with magnesium sulfate
  3. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-510a24e63d234851a5089c8d12a03bcf
Source dataset
uspto-grants-1996_02
Patent number
US05492830

Reaction notes

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