Reaction #927264

Reaction equation

4-bromo-pent4-enoic acid ethyl ester

bromoform

N,N′-dibenzyl-N,N,N′,N′-tetramethylethylenediammonium dibromide

potassium hydroxide

→

3-(1,2,2-tribromo-cyclopropyl)-propionic acid ethyl ester

Yield 66.4%

Solvents

methylene chloride

Conditions

Workup

1. 1
   OtherThe resulting mixture was transferred to a separatory funnel
2. 2
   Otherthe phases were separated
3. 3
   OtherThe solvent was removed from the isolated organic layer in vacuo
4. 4
   ExtractionThis residue was extracted with hexanes from water
5. 5
   OtherThe resulting mixture was transferred to a separatory funnel
6. 6
   Otherthe phases were separated
7. 7
   DryingThe organic layer was dried over MgSO4
8. 8
   Filtrationfiltered
9. 9
   OtherThe solvent was removed from the filtrate in vacuo
10. 10
    OtherThis residue was purified by column chromatography with 10% diethyl ether/hexanes

Procedure

To a solution made of 12.12 g (58 mmol) of 4-bromo-pent4-enoic acid ethyl ester and 51 g (202 mmol) of bromoform and 100 g of methylene chloride was added 2.0 g of N,N′-dibenzyl-N,N,N′,N′-tetramethylethylenediammonium dibromide and 27.1 g (218 mmol) of 45% aqueous potassium hydroxide. The reaction mixture was stirred rapidly for 4 days. The resulting mixture was transferred to a separatory funnel and the phases were separated. The solvent was removed from the isolated organic layer in vacuo. This residue was extracted with hexanes from water. The resulting mixture was transferred to a separatory funnel and the phases were separated. The organic layer was dried over MgSO4 and filtered. The solvent was removed from the filtrate in vacuo. This residue was purified by column chromatography with 10% diethyl ether/hexanes to yield 14.6 g (66.3% of theory) of 3-(1,2,2-tribromo-cyclopropyl)-propionic acid ethyl ester.

Source