Ethanol → (S)-(+)-ethyl 2-methyl-5-phenylpentanoate

HRID 59691Notes

Reaction equation

HRID 59691 reaction equation
[CH3:1][C@@H:2]([CH2:6][CH2:7][CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)[C:3]([OH:5])=[O:4].[CH2:15](O)[CH3:16]>S(=O)(=O)(O)O>[CH3:1][C@@H:2]([CH2:6][CH2:7][CH2:8][C:9]1[CH:10]=[CH:11][CH:12]=[CH:13][CH:14]=1)[C:3]([O:5][CH2:15][CH3:16])=[O:4]

Participants

4

Reactant 2

HCID 702EthanolHCID 90054467(S)-2-methyl-5-phenylpentanoic acid

Product 1

HCID 90054464(S)-(+)-ethyl 2-methyl-5-phenylpentanoateYield 91%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidCatalyst

Procedure

To a solution consisting of (S)-(+)-2-methyl-5-phenylpentanoic acid (20mb(i), 2.3 g, 12 mmol) in ethanol (200 mL) was added 4 drops of concentrated sulfuric acid. The stirring reaction mixture was brought to reflux overnight and was subsequently cooled and concentrated under vacuum. The residue was diluted with ethyl acetate and washed twice with brine. The organic layer was dried over sodium sulfate, filtered, and concentrated under vacuum to afford the title compound (2.4 g, 91%) as a clear oil; TLC Rf 0.66 (solvent system: 15:85:1 v/v/v ethyl acetate-heptane-acetic; MS (ESI+) m/z 221.2 (M+H)+; 1H-NMR (CDCl3) δ 7.29-7.25 (m, 2H), 7.21-7.13 (m, 3H), 4.12 (q, J=6.96 Hz, 2H), 2.64-2.57 (m, 2H), 2.48-2.39 (m, 1H), 1.75-1.54 (m, 3H), 1.52-1.41 (m, 1H), 1.24 (t, J=7.14 Hz, 3H) 1.16-1.11 (m, 3H); [α]Tλ=α/cl, [α]21.9D=+0.101/(0.01506 g/1.5 ml)(0.5)=+20.12° (c=1, CHCl3).

Workup

  1. customThe stirring reaction mixture
  2. temperatureto reflux overnight
  3. temperaturewas subsequently cooled
  4. concentrationconcentrated under vacuum
  5. additionThe residue was diluted with ethyl acetate
  6. washwashed twice with brine
  7. dry with materialThe organic layer was dried over sodium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-98c78ffe2f3f4a85b161146ae6806719
Source dataset
uspto-grants-2016_09
Patent number
US09440919B2

Reaction notes

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