Acetic Acid → (1R)-(+)-cis-Permethric acid

HRID 127044Notes

Reaction equation

HRID 127044 reaction equation
C(O)(=O)C.[CH3:5][C:6]1([CH3:17])[C@H:11]2[C@@H:7]1[C@H:8]([C:13](Cl)([Cl:15])[Cl:14])[O:9][C:10]2=[O:12]>CCOCC.O.[Zn]>[Cl:14][C:13]([Cl:15])=[CH:8][C@H:7]1[C@@H:11]([C:10]([OH:12])=[O:9])[C:6]1([CH3:5])[CH3:17]

Participants

6

Reactant 2

HCID 176Acetic AcidHCID 10538220(1R,4R,5S)-6,6-dimethyl-2-oxo-4-trichloromethyl-3-oxabicyclo[3.1.0]hexane

Product 1

HCID 673647(1R)-(+)-cis-Permethric acidYield 18%

Reagents, catalysts & solvents 3

HCID 23994ZincCatalystHCID 962WaterSolventHCID 3283Diethyl EtherSolvent3×

Procedure

To a suspension of finely divided zinc dust (0.81 g, 1.23 mmole) in acetic acid (0.99 g, 1.64 mmole) and 4 ml of ether was added, under nitrogen, a solution of (1R,4R,5S)-6,6-dimethyl-2-oxo-4-trichloromethyl-3-oxabicyclo[3.1.0]hexane (0.50 g, 1.84 mmole) from Example IA.8.(a) in 4 ml of ether. The reaction was monitored by glpc. When the glpc results indicated almost complete conversion, the reaction mixture was diluted with additional ether and water, filtered through Celite filter aid, and the organic layer was separated, dried, and evaporated to a yellow oil which was chromatographed on two 20×20 cm preparative tlc plates with CH2Cl2 as eluent. The slow running acid band was removed, extracted with CH2Cl2, and the extract was filtered and evaporated to afford (1R,3R)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid (68 mg, 18% isolated yield). The optical rotation of the acid prepared in a second identical run was measured; [α]D31 =+6.2 (hexane).

Workup

  1. additionwas added, under nitrogen
  2. customWhen the glpc results
  3. filtrationfiltered through Celite
  4. filtrationfilter aid
  5. customthe organic layer was separated
  6. customdried
  7. customevaporated to a yellow oil which
  8. customwas chromatographed on two 20×20 cm preparative tlc plates with CH2Cl2 as eluent
  9. customThe slow running acid band was removed
  10. extractionextracted with CH2Cl2
  11. filtrationthe extract was filtered
  12. customevaporated

Sources & evidence

ORD record
ord-7ee9ca9c0fec4961940bca4b76c7c1c2
Source dataset
uspto-grants-1981_03
Patent number
US04254282

Reaction notes

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