(2R)-5-Phenyl-2-methylpentanoic acid → (R)-(-)-ethyl 2-methyl-5-phenylpentanoate

HRID 59699Notes

Reaction equation

HRID 59699 reaction equation
C[C@H](CCCC1C=CC=CC=1)C(O)=O.[CH3:15][C@@H:16]([CH2:22][CH2:23][CH2:24][C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)[C:17]([O:19][CH2:20][CH3:21])=[O:18]>>[CH3:15][C@H:16]([CH2:22][CH2:23][CH2:24][C:25]1[CH:26]=[CH:27][CH:28]=[CH:29][CH:30]=1)[C:17]([O:19][CH2:20][CH3:21])=[O:18]

Participants

3

Reactant 2

HCID 12153395(2R)-5-Phenyl-2-methylpentanoic acidHCID 90054464(S)-(+)-ethyl 2-methyl-5-phenylpentanoate

Product 1

HCID 90054516(R)-(-)-ethyl 2-methyl-5-phenylpentanoateYield 88%

Procedure

(R)-(−)-Ethyl 2-methyl-5-phenylpentanoate was prepared from 20mc(i) (20.8 g) in the same manner (S)-(+)-ethyl 2-methyl-5-phenylpentanoate was prepared from 20mb(i) as described above. The residue was purified by silica gel chromatography. Elution with ethyl acetate-heptane (5:95 v/v) afforded the title compound (21.0 g, 88%) as a clear oil; TLC Rf 0.66 (solvent system: 15:85:1 v/v/v ethyl acetate-heptane-acetic acid); MS (ESI+) m/z 221.2 (M+H)+; 1H-NMR (CDCl3) δ 7.32-7.26 (m, 2H), 7.20-7.14 (m, 3H), 4.11 (q, J=7.32 Hz, 2H), 2.64-2.57 (m, 2H), 2.48-2.39 (m, 1H), 1.75-1.53 (m, 3H), 1.52-1.41 (m, 1H), 1.27-1.21 (m, 3H), 1.13 (d, J=6.96 Hz, 3H,); [α]Tλ=α/cl, [α]21.9D=−0.114/(0.01771 g/1.5 mL)(0.5)=−19.31° (c=1.18, CHCl3).

Workup

  1. customwas prepared from 20mb(i)
  2. customThe residue was purified by silica gel chromatography
  3. washElution with ethyl acetate-heptane (5:95 v/v)

Sources & evidence

ORD record
ord-916e40aecf02473fa9d7e5f7e2084e16
Source dataset
uspto-grants-2016_09
Patent number
US09440919B2

Reaction notes

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