(+-)-Pantolactone → Keto-pantoyllactone

HRID 399614

Reaction equation

HRID 399614 reaction equation
[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

Participants

6

Reactant 3

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

Product 1

HCID 39Keto-pantoyllactoneYield 71.1%

Reagents, catalysts & solvents 2

HCID 2724126TempoCatalystHCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

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 60 mg (0.28 mmol) of TEMPO derative B in 2 ml of methylene chloride was dosed in within 10 minutes. The temperature was held at 0°-3° C. by constant cooling. The reaction had finished after 3 hours. The white precipitate was filtered off and the filtrate was treated with sodium bisulphite solution in order to reduce the excess trichloroisocyanuric acid. Working up of the reaction mixture and subsequent recrystallization of the crude product gave 3.5 g (71%) of ketopantolactone, GC content: 99.6% (area percent).

Workup

  1. customwas dosed in within 10 minutes
  2. customwas held at 0°-3° C. by constant cooling
  3. filtrationThe white precipitate was filtered off
  4. additionthe filtrate was treated with sodium bisulphite solution in order
  5. customWorking up of the reaction mixture and subsequent recrystallization of the crude product

Sources & evidence

ORD record
ord-eb9f6d5bd4584a7e902f4f376752d67b
Source dataset
uspto-grants-1998_10
Patent number
US05821374

Linked notes

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