Cornforth reagent → 1-tert-Butyl 2-methyl (2R)-4-oxopyrrolidine-1,2-dicarboxylate

HRID 1507903ノート

反応式

HRID 1507903 の反応式
[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[OH:22][C@H:23]1[CH2:27][N:26]([C:28]([O:30][C:31]([CH3:34])([CH3:33])[CH3:32])=[O:29])[C@@H:25]([C:35]([O:37][CH3:38])=[O:36])[CH2:24]1>ClCCl>[O:22]=[C:23]1[CH2:27][N:26]([C:28]([O:30][C:31]([CH3:32])([CH3:33])[CH3:34])=[O:29])[C@@H:25]([C:35]([O:37][CH3:38])=[O:36])[CH2:24]1

参加物

4

反応物 2

HCID 2724130Cornforth reagentHCID 6951202(2R,4R)-4-Hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

生成物 1

HCID 105381811-tert-Butyl 2-methyl (2R)-4-oxopyrrolidine-1,2-dicarboxylate収率 131%

試薬・触媒・溶媒 1

HCID 6344Dichloromethane溶媒

実験手順

To slurry of pyridinium dichromate (9.97 g, 26.5 mmol) in dichloromethane (60 mL) at rt was added (2R,4R)-1-tert-butyl 2-methyl 4-hydroxypyrrolidine-1,2-dicarboxylate (5.00 g, 20.39 mmol) in several portions. The resulting mixture was stirred overnight at rt. Celite (5 g) was added and the mixture stirred for 40 min, filtered and the filter cake was rinsed with additional dichloromethane (50 mL×3). The resulting filtrate was concentrated and toluene (40 mL) was added followed by concentration again under vacuum to give ˜6.5 g of a brown syrup as the crude product. Purification by flash silica gel chromatography (120 g column, EtOAc in hexane, 0 to 100% gradiant, 85 mL/min) afforded 4.18 g (84%) of the title compound as a white solid. LCMS (condition A): m/z 144 (M-Boc) −ve. 1H NMR (400 MHz, CDCl3) δ ppm 4.64-4.89 (1 H, m), 3.84-3.96 (2 H, m), 3.77 (3 H, s), 2.81-3.10 (1 H, m), 2.59 (1 H, dd, J=18.93, 1.76 Hz), 1.52 (9 H, s).

後処理

  1. additionCelite (5 g) was added
  2. stirringthe mixture stirred for 40 min
  3. filtrationfiltered
  4. washthe filter cake was rinsed with additional dichloromethane (50 mL×3)
  5. concentrationThe resulting filtrate was concentrated
  6. additiontoluene (40 mL) was added
  7. concentrationfollowed by concentration again under vacuum

出典と根拠

ORDレコード
ord-d603aa3ad0c54346afc880545fa3cc32
出典データセット
uspto-grants-2015_12
特許番号
US09221826B2

反応ノート

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