(2S)-2-Bromo-3-methylbutanoic acid → (R)-2-benzoylthio-3-methylbutanoic acid

HRID 409187노트

반응식

HRID 409187 반응식
Br[C@@H:2]([CH:6]([CH3:8])[CH3:7])[C:3]([OH:5])=[O:4].[C:9]([O-:17])(=[S:16])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1.[Cs+]>CN(C=O)C.CCOCC>[C:9]([S:16][C@H:2]([CH:6]([CH3:8])[CH3:7])[C:3]([OH:5])=[O:4])(=[O:17])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1

참가 물질

5

반응물 2

HCID 179487(2S)-2-Bromo-3-methylbutanoic acidHCID 23707493Cesium thiobenzoate

생성물 1

HCID 13662423(R)-2-benzoylthio-3-methylbutanoic acid수율 75.5%

시약·촉매·용매 2

HCID 3283Diethyl Ether용매HCID 6228Dimethylformamide용매

실험 절차

To a solution of (S)-(−)-2-bromo-3-methylbutyric acid (4.20 g, 23.2 mmol) in DMF (41 mL) was added cesium thiobenzoate (6.08 g, 22.5 mmol). The mixture was stirred at rt for 20 h. The resulting solution was diluted with ether (200 mL) and washed with H2O (4×40 mL). The ethereal layer was dried (Na2SO4), and concentrated. The crude residue was recrystallized from hexanes to afford (R)-2-benzoylthio-3-methylbutanoic acid as a pale yellow solid (4.05 g, 75%); 1H NMR (300 MHz, CDCl3) δ 1.09 (d, J=7.4 Hz, 3H), 1.11 (d, J=7.4 Hz, 3H), 2.40 (m, 1H), 4.37 (d, J=5.9 Hz, 1H), 7.45 (t, J=7.4 Hz, 2H), 7.57 (t, J=7.4 Hz, 1H), 7.97 (d, J=7.4 Hz, 2H), 11.9 (br s, 1H); 13C NMR (75 MHz, CDCl3) δ19.8, 20.6, 30.5, 53.1, 127.6, 128.8, 133.9, 136.3, 177.9, 190.3; IR (neat) 3100, 2967, 1709, 1669 cm−1; [α]D22=+95.6 (c 1, CH2Cl2). All spectral data was identical to that previously published (Strijtveen, B.; Kellogg, R. M. J. Org. Chem. 1986, 51, 3664).

후처리

  1. washwashed with H2O (4×40 mL)
  2. dry with materialThe ethereal layer was dried (Na2SO4)
  3. concentrationconcentrated
  4. customThe crude residue was recrystallized from hexanes

출처 및 근거

ORD 기록
ord-dddc34358d6b44a59d8071f529b25483
출처 데이터셋
uspto-grants-2014_06
특허 번호
US08759378B2

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