Pyridine → (2R)-1-((tert-butoxy)carbonyl)-4-oxopyrrolidine-2-carboxylic acid

HRID 602330Notes

Reaction equation

HRID 602330 reaction equation
N1C=CC=CC=1.[C:7]([N:14]1[CH2:21][C@H:20]([OH:22])[CH2:19][C@@H:15]1[C:16]([OH:18])=[O:17])([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8]>ClCCl.[O-2].[Cr+6].[O-2].[O-2]>[C:7]([N:14]1[CH2:21][C:20](=[O:22])[CH2:19][C@@H:15]1[C:16]([OH:18])=[O:17])([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8]

Participants

5

Reactant 2

HCID 1049PyridineHCID 688616N-Boc-cis-4-hydroxy-D-proline

Product 1

HCID 41098094(2R)-1-((tert-butoxy)carbonyl)-4-oxopyrrolidine-2-carboxylic acid

Reagents, catalysts & solvents 2

HCID 10219390chromium (VI) trioxideCatalystHCID 6344DichloromethaneSolvent2×

Procedure

6.1 12.2 g (122 mmol) of chromium(VI) oxide are added to a mixture, held at 0° C., of 22 ml of pyridine and 50 ml of dichloromethane, and the mixture is stirred at the same temperature for 30 minutes. The solution is allowed to warm to room temperature, and a solution of 5.00 g of cis-Boc-4-hydroxy-D-proline in 80 ml of dichloromethane is added dropwise over the course of 5 minutes. After stirring at room temperature for 1 hour, the solution is filtered, and the filtrate is evaporated. The residue is partitioned between 1N HCl and tert-butyl methyl ether. The organic phase is dried over sodium sulfate, evaporated and recrystallised from diethyl ether/petroleum ether, giving Boc-4-keto-D-proline as a colourless solid; ESI 130.

Workup

  1. stirringAfter stirring at room temperature for 1 hour
  2. filtrationthe solution is filtered
  3. customthe filtrate is evaporated
  4. customThe residue is partitioned between 1N HCl and tert-butyl methyl ether
  5. dry with materialThe organic phase is dried over sodium sulfate
  6. customevaporated
  7. customrecrystallised from diethyl ether/petroleum ether

Sources & evidence

ORD record
ord-17a2e3e9cfd24f38818f0260f37ac147
Source dataset
uspto-grants-2011_03
Patent number
US07906516B2

Reaction notes

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