D-Allothreonine → (2R,3R)-2-(5-phenylpentoxycarbonylamino)-3-hydroxy-butanoic acid

HRID 530523Notes

Reaction equation

HRID 530523 reaction equation
[NH2:1][C@@H:2]([C:6]([OH:8])=[O:7])[C@@H:3]([CH3:5])[OH:4].[C:9]([O-:12])(O)=[O:10].[Na+].[C:14]1([CH2:20][CH2:21][CH2:22][CH2:23][CH2:24]C2C(=O)N(C([O-])=O)C=CC=2)[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1>O.C1COCC1>[C:14]1([CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][O:12][C:9]([NH:1][C@H:2]([C@H:3]([OH:4])[CH3:5])[C:6]([OH:8])=[O:7])=[O:10])[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Participants

6

Reactant 3

HCID 90624D-AllothreonineHCID 516892Sodium BicarbonateHCID 866999375-Phenyl-pentyl-2-oxopyridine-1-carboxylate

Product 1

HCID 86699949(2R,3R)-2-(5-phenylpentoxycarbonylamino)-3-hydroxy-butanoic acidYield 89.6%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a stirred mixture of D-allo-threonine (0.10 g, 0.83 mmol) and NaHCO3 (0.11 g, 1.25 mmol) in H2O (3.5 mL), the crude mixture containing 5-phenyl-pentyl-2-pyridyl-carbonate and 5-phenyl-pentyl-2-oxopyridine 1-carboxylate (0.36 g, 1.25 mmol) in THF (3.0 mL) was added. After 15 h at rt, the crude mixture was rotary evaporated to remove the organics and subsequently extracted with Et2O (3×5 mL). The aqueous phase was acidified with 2.0 M HCl solution to pH 2-3 and subsequently extracted with EtOAc (3×10 mL). The organic fraction was dried over Na2SO4, filtered and concentrated to dryness to afford the title compound (0.23 g, 89%) as colorless oil, which was used in the next step without further purification. MS (ESI) m/z: 332 [M−Na]+, 327 [M−NH4]+; (ESI) m/z: 308 [M−H]−. 1H NMR (DMSO-d6) δ 1.08 (d, J=6.0 Hz, 3H), 1.28-1.39 (m, 2H), 1.59 (t, J=9.0 Hz, 4H), 2.57 (t, J=7.7 Hz, 2H), 3.80-4.00 (m, 4H), 7.10 (d, J=8.1 Hz, 1H), 7.13-7.22 (m, 3H), 7.22-7.31 (m, 2H), 12.33 (s, 1H).

Workup

  1. additionwas added
  2. customthe crude mixture was rotary evaporated
  3. customto remove the organics and
  4. extractionsubsequently extracted with Et2O (3×5 mL)
  5. extractionsubsequently extracted with EtOAc (3×10 mL)
  6. dry with materialThe organic fraction was dried over Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated to dryness

Sources & evidence

ORD record
ord-4fcc666d24e34c189d47561b94019a17
Source dataset
uspto-grants-2016_05
Patent number
US09353075B2

Reaction notes

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