Citric Acid → (RS)-2-methyl-4-methylidene-3-ethyl-2-cyclopenten-1-yl (1R)-trans-3-(2,2-dichloro-vinyl)-2,2-dimethylcyclopropanecarboxylate

HRID 1379934Notes

Reaction equation

HRID 1379934 reaction equation
[Cl:1][C:2]([Cl:12])=[CH:3][C@@H:4]1[C@@H:6]([C:7](Cl)=[O:8])[C:5]1([CH3:11])[CH3:10].[CH3:13][C:14]1[CH:15]([OH:22])[CH2:16][C:17](=[CH2:21])[C:18]=1[CH2:19][CH3:20].N1C=CC=CC=1.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C1(C)C=CC=CC=1.C(C1C=C(C)C=C(C(C)(C)C)C=1O)(C)(C)C>[Cl:1][C:2]([Cl:12])=[CH:3][C@@H:4]1[C@@H:6]([C:7]([O:22][CH:15]2[CH2:16][C:17](=[CH2:21])[C:18]([CH2:19][CH3:20])=[C:14]2[CH3:13])=[O:8])[C:5]1([CH3:11])[CH3:10]

Participants

7

Reactant 4

HCID 311Citric AcidHCID 1049PyridineHCID 6454308(1R,3S)-3-(2,2-Dichloroethenyl)-2,2-dimethylcyclopropanecarbonyl chlorideHCID 15389976(RS)-2-methyl-4-methylidene-3-ethylcyclopent-2-en-1-ol

Product 1

HCID 15389982(RS)-2-methyl-4-methylidene-3-ethyl-2-cyclopenten-1-yl (1R)-trans-3-(2,2-dichloro-vinyl)-2,2-dimethylcyclopropanecarboxylateYield 86.3%

Reagents, catalysts & solvents 2

HCID 314042,6-Di-tert-butyl-4-methylphenolCatalystHCID 1140TolueneSolvent

Procedure

625 mg of (1R)-trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid chloride was added under ice-water cooling to a mixed solution of 400 mg of (RS)-2-methyl-4-methylidene-3-ethylcyclopent-2-en-1-ol, 5 mg of 2,6-di-t-butyl-4-methylphenol and 274 mg of pyridine in 6 ml of toluene. The reaction was continued at an ambient temperature for eight hours. The reaction solution was added to a 5% citric acid solution under ice-water cooling, and extracted three times with diethyl ether. The combined ether layer was washed successively with a saturated sodium hydrogencarbonate solution and a saturated sodium chloride solution, and dried over anhydrous magnesium sulfate. After removal of the solvent under reduced pressure, the residue was subjected to silica gel column chromatography to yield 781 mg of (RS)-2-methyl-4-methylidene-3-ethyl-2-cyclopenten-1-yl (1R)-trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate (Compound No.5). Yield 82%. (Eluent: n-hexane/ethyl acetate=30/1, 2,6-di-t-butyl-4-methylphenol 0.1%) nD23 1.5251

Workup

  1. extractionextracted three times with diethyl ether
  2. washThe combined ether layer was washed successively with a saturated sodium hydrogencarbonate solution
  3. dry with materiala saturated sodium chloride solution, and dried over anhydrous magnesium sulfate
  4. customAfter removal of the solvent under reduced pressure

Sources & evidence

ORD record
ord-f112712c5f5b4fe0afb7363dcc802169
Source dataset
uspto-grants-1997_09
Patent number
US05672779

Reaction notes

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