(+-)-Pantolactone → Keto-pantoyllactone

HRID 399613

反応式

HRID 399613 の反応式
[OH:1][CH:2]1[C:7]([CH3:9])([CH3:8])[CH2:6][O:5][C:3]1=[O:4].C([O-])(=O)C.[Na+].ClN1C(=O)N(Cl)C(=O)N(Cl)C1=O>C(Cl)Cl.CC1(C)N([O])C(C)(C)CCC1>[CH3:8][C:7]1([CH3:9])[C:2](=[O:1])[C:3](=[O:4])[O:5][CH2:6]1

参加物

6

反応物 3

HCID 989(+-)-PantolactoneHCID 6909Trichloroisocyanuric AcidHCID 517045Sodium Acetate

生成物 1

HCID 39Keto-pantoyllactone収率 86%

試薬・触媒・溶媒 2

HCID 2724126Tempo触媒HCID 6344Dichloromethane溶媒2 回

反応条件

温度
0 °C

実験手順

5 g (38.4 mmol) of 2-hydroxy-3,3-dimethyl-γ-butyrolactone (pantolactone) were dissolved in 118 ml of methylene chloride in a 200 ml sulphonation flask. 3.3 g (40.2 mmol) of sodium acetate and 3.6 g (15.5 mmol) of trichloroisocyanuric acid were added thereto. The mixture was cooled to 0° C. while stirring. A solution of 38.2 mg (0.24 mmol) of TEMPO in 2 ml of methylene chloride was dosed in within 10 minutes. The temperature was held at 0°-3° C. by constant cooling. After a reaction period of 7 hours the white precipitate was filtered off. The filtrate was concentrated. Chromatography of the residue (SiO2, toluene/ethyl acetate 85:15) and subsequent recrystallization of the chromatographed product gave 4.23g (86%) of ketopantolactone, m.p. 67.5°-68° C., GC content: 100% (area percent).

後処理

  1. customwas dosed in within 10 minutes
  2. customwas held at 0°-3° C. by constant cooling
  3. customAfter a reaction period of 7 hours the white precipitate
  4. filtrationwas filtered off
  5. concentrationThe filtrate was concentrated
  6. customChromatography of the residue (SiO2, toluene/ethyl acetate 85:15) and subsequent recrystallization of the chromatographed product

出典と根拠

ORDレコード
ord-76b8e3935a124c7b9a760f018c32dbfa
出典データセット
uspto-grants-1998_10
特許番号
US05821374

関連ノート

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