(E)-(R)-4-tert-butoxycarbonylamino-2-methyl-pent-2-enoic acid ethyl ester → (2R,4R)-4-tert-butoxycarbonylamino-2-methyl-pentanoic acid ethyl ester

HRID 1945049Notes

Reaction equation

HRID 1945049 reaction equation
[CH2:1]([O:3][C:4](=[O:18])/[C:5](/[CH3:17])=[CH:6]/[C@H:7]([NH:9][C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH3:8])[CH3:2]>C(OCC)(=O)C.[Pt]>[CH2:1]([O:3][C:4](=[O:18])[C@H:5]([CH3:17])[CH2:6][C@H:7]([NH:9][C:10]([O:12][C:13]([CH3:14])([CH3:16])[CH3:15])=[O:11])[CH3:8])[CH3:2]

Participants

4

Reactant 1

HCID 86648196(E)-(R)-4-tert-butoxycarbonylamino-2-methyl-pent-2-enoic acid ethyl ester

Product 1

HCID 86648195(2R,4R)-4-tert-butoxycarbonylamino-2-methyl-pentanoic acid ethyl ester

Reagents, catalysts & solvents 2

HCID 23939PlatinumCatalystHCID 8857Ethyl AcetateSolvent

Procedure

Next, a solution of (E)-(R)-4-tert-butoxycarbonylamino-2-methyl-pent-2-enoic acid ethyl ester (1.83 g, 7.11 mmol) in ethyl acetate (75 mL) is hydrogenated over 10% Pt/C (183 mg) at 1 atm for 18 hours. The catalyst is filtered through Celite and the solvent is removed under reduced pressure. The residue is purified by chiral HPLC to afford (2R,4R)-4-tert-butoxycarbonylamino-2-methyl-pentanoic acid ethyl ester, 1H-NMR (400 MHz, CDCl3); 6 ppm 1.13 (t, 3H), 1.18 (m, 3H), 1.26 (t, 3H), 1.43 (s, 9H), 1.81 (s, 1H), 2.50 (m, 1H), 3.72 (m broad, 1H), 4.14 (m, 2H), 4.33 (m broad, 1H).

Workup

  1. filtrationThe catalyst is filtered through Celite
  2. customthe solvent is removed under reduced pressure
  3. customThe residue is purified by chiral HPLC

Sources & evidence

ORD record
ord-3538410d92a546c9a8b08b74faaf06b2
Source dataset
uspto-grants-2013_03
Patent number
US08394853B2

Reaction notes

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