Reaction #1747826

Reaction equation

ethynylmagnesium bromide

3-ethoxy-2-cyclohexen-1-one

HCl

→

3-Ethynyl-2-cyclohexen-1-one

Solvents

tetrahydrofuran

tetrahydrofuran

Conditions

Workup

1. 1
   workup.STIRRINGAfter stirring for 15 min the acidic phase
2. 2
   Extractionwas extracted with dichloromethane (5×50 mL)
3. 3
   WashThe combined organic extracts were washed with water (2×50 mL)
4. 4
   Dryingdried (MgSO4)
5. 5
   OtherEvaporation of the solvent
6. 6
   Othergave an oil that
7. 7
   Otherwas purified by column chromatography (silica, ethyl acetate/hexane 1:9)
8. 8
   Otherto yield a yellow oil, 2.71 g, 22.6 mmol, 84%)

Procedure

To a solution of 0.5N ethynylmagnesium bromide in tetrahydrofuran (100 mL) was added under N2 and stirring 3-ethoxy-2-cyclohexen-1-one (3.75 g, 26.8 mmol) in tetrahydrofuran (12.5 mL). The mixture was stirred at RT for 20 h when it was acidified with 1N HCl (200 mL). After stirring for 15 min the acidic phase was extracted with dichloromethane (5×50 mL). The combined organic extracts were washed with water (2×50 mL) and dried (MgSO4). Evaporation of the solvent gave an oil that was purified by column chromatography (silica, ethyl acetate/hexane 1:9) to yield a yellow oil, 2.71 g, 22.6 mmol, 84%). Analysis were in agreement with literature data.

Source