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

HRID 1026148ノート

反応式

HRID 1026148 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>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 178418443HCID 178418443、化合物

生成物 1

HCID 545314052,2-Dimethyloxazolidine-3-carboxylic acid tert-butyl ester収率 56.9%

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 (15.5 g; CAS 147959-19-1) in dry diethyl ether (100 ml) under an argon atmosphere at room temperature was added dropwise a solution of ethylmagnesium bromide in diethyl ether (42.6 ml, 3 M solution) and stirring continued for 1 hour. The reaction mixture was then quenched by careful addition of water (10 ml) and the mixture was then filtered through decalite. The filtrate was washed sequentially with water and with saturated brine and then the organic phase was separated, 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-butyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (7.30 g) from fractions eluting first and (S)-4-(S)-2-hydroxy-butyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (6.44 g) from fractions eluting later, both compounds as colourless oils. (S)-4-(R)-2-Hydroxy-butyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester: 1H NMR δ (CDCl3, 300 MHz): 4.52 (1H, br. D, J=3.3 Hz), 4.23 (1H, m), 4.00 (1H, dd, J=8.7 & 5.4 Hz), 3.66 (1H, d, J=8.7 Hz), 3.40 (1H, m), 1.79 (1H, td, J=11.4 & 2.1 Hz), 1.60-1.44 (16H, m), 0.95 (3H, t, J=7.5 Hz). (S)-4-(S)-2-Hydroxy-butyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester: 1H NMR δ (CDCl3, 300 MHz): 4.12 (1H, m), 3.98 (1H, dd, J=9.0 & 5.7 Hz), 3.82 (1H, m), 3.55 (1H, m), 2.88 (1H, br. s), 1.79 (1H, m), 1.70-1.40 (16H, m), 0.95 (3H, t, J=7.5 Hz).

後処理

  1. customThe reaction mixture was then quenched by careful addition of water (10 ml)
  2. filtrationthe mixture was then filtered through decalite
  3. washThe filtrate was washed sequentially with water and with saturated brine
  4. customthe organic phase was separated
  5. dry with materialdried over sodium sulphate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. 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-00198d3a8b754fd1b18522a8ab32dc90
出典データセット
uspto-grants-2014_05
特許番号
US08729113B2

反応ノート

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