Reaction #40887

Reaction equation

Sodium hydroxide

hydrogen peroxide

ethyl {3-[(2E)-but-2-en-1-yl]-2-oxocyclohexyl}acetate

borane

→

desired title compound

2—Ethyl (2-ethyl-7a-hydroxyoctahydro-1-benzofuran-7-yl)acetate

Solvents

brine

tetrahydrofuran

tetrahydrofuran

Conditions

Workup

1. 1
   workup.STIRRINGto stir at room temperature for 1 h
2. 2
   Extractionextracted three times with dichloromethane
3. 3
   WashThe combined organics were washed twice with brine
4. 4
   Dryingdried over sodium sulfate
5. 5
   Concentrationconcentrated in vacuo
6. 6
   Otherpurified by column chromatography (50% EtOAc/hexanes)

Procedure

To a stirred solution of ethyl {3-[(2E)-but-2-en-1-yl]-2-oxocyclohexyl}acetate (565 mg, 2.37 mmol) in tetrahydrofuran (20 ml) at 0° C. was added borane.tetrahydrofuran complex (1 M in tetrahydrofuran, 3.56 ml, 3.56 mmol) and the reaction allowed to stir at 0° C. for 35 min. Sodium hydroxide (4N, 5.6 ml) and hydrogen peroxide (5.6 ml) were added and the reaction allowed to stir at room temperature for 1 h. Diluted with brine, then extracted three times with dichloromethane. The combined organics were washed twice with brine, dried over sodium sulfate, concentrated in vacuo and purified by column chromatography (50% EtOAc/hexanes). The desired title compound (345 mg) was obtained as a colourless oil as a complex mixture of diastereomers.

Source