(S)-Tert-butyl 2,2-dimethyl-4-(2-oxoethyl)oxazolidine-3-carboxylate → 2,2-Dimethyloxazolidine-3-carboxylic acid tert-butyl ester

HRID 1807921ノート

反応式

HRID 1807921 の反応式
[C:1]([O:5][C:6]([N:8]1[C@@H:12](CC=O)[CH2:11][O:10][C:9]1([CH3:17])[CH3:16])=[O:7])([CH3:4])([CH3:3])[CH3:2].C[Mg]Br>C(OCC)C>[C:1]([O:5][C:6]([N:8]1[CH2:12][CH2:11][O:10][C:9]1([CH3:17])[CH3:16])=[O:7])([CH3:4])([CH3:2])[CH3:3]

参加物

4

反応物 2

HCID 10586317(S)-Tert-butyl 2,2-dimethyl-4-(2-oxoethyl)oxazolidine-3-carboxylateHCID 178418573HCID 178418573、化合物

生成物 1

HCID 545314052,2-Dimethyloxazolidine-3-carboxylic acid tert-butyl ester収率 59.3%

試薬・触媒・溶媒 1

HCID 3283Diethyl Ether溶媒2 回

実験手順

To a stirred solution of (S)-2,2-dimethyl-4-(2-oxo-ethyl)-oxazolidine-3-carboxylic acid tert-butyl ester (12.0 g; CAS 147959-19-1) in dry diethyl ether (200 ml) under an argon atmosphere at room temperature was added dropwise a solution of methylmagnesium bromide in diethyl ether (49.3 ml, 3 M solution) and stirring continued overnight. The reaction mixture was then quenched by careful addition of water and extracted twice with ethyl acetate. The combined organic phases were dried over sodium sulphate, filtered and concentrated in vacuo. The reside was purified by column chromatography (SiO2; gradient: heptane/EtOAc 100:0→50:50) to give (S)-4-(R)-2-hydroxy-propyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (5.89 g) from fractions eluting first and (S)-4-(S)-2-hydroxy-propyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (4.07 g) from fractions eluting later, both compounds as light yellow oils. (S)-4-(R)-2-hydroxy-propyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester: 1H NMR δ (CDCl3, 300 MHz): 4.60 (1H, br. D, J=3.3 Hz), 4.23 (1H, m), 4.00 (1H, dd, J=8.7 & 5.4 Hz), 3.71 (1H, m), 3.65 (1H, d, J=8.7 Hz), 1.76 (1H, td, J=11.4 & 2.1 Hz), 1.61-1.46 (16H, m), 1.20 (3H, d, J=6.3 Hz). (S)-4-(S)-2-hydroxy-propyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester: 1H NMR δ (CDCl3, 300 MHz): 4.13 (1H, m), 3.98 (1H, m), 3.85-3.60 (2H, m), 2.50 (1H, br. s), 1.80 (1H, m), 1.60-1.49 (16H, m), 1.22 (3H, d, J=6.3 Hz).

後処理

  1. customThe reaction mixture was then quenched by careful addition of water
  2. extractionextracted twice with ethyl acetate
  3. dry with materialThe combined organic phases were dried over sodium sulphate
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customThe reside was purified by column chromatography (SiO2; gradient: heptane/EtOAc 100:0→50:50)

出典と根拠

ORDレコード
ord-76d2c490273c4b71a8ebf03981f8a706
出典データセット
uspto-grants-2013_01
特許番号
US08357712B2

反応ノート

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