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

HRID 508135ノート

反応式

HRID 508135 の反応式
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

参加物

5

反応物 2

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

生成物 1

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

試薬・触媒・溶媒 2

HCID 3283Diethyl Ether溶媒HCID 6228Dimethylformamide溶媒

実験手順

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) δ 19.8, 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).

後処理

  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

出典と根拠

ORDレコード
ord-2362a4e5d24f45539b32b7995da752fc
出典データセット
uspto-grants-2015_08
特許番号
US09095565B2

反応ノート

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