Reaction #81588

Reaction equation

acetic anhydride

acetic acid

6-bromo-l,2,3,4-tetrahydro-1,1-dimethylnaphthalene

6-bromo-1,2,3,4-tetrahydro-1,1-dimethylnaphthalene

Compound F

6-bromo-1,2,3,4-tetrahydro-1,1-dimethylnaphthalene

→

title compound

7-Bromo-3,4-dihydro-4,4-dimethyl-naphthalen-1(2H)-one

Solvents

benzene

Conditions

Workup

1. 1
   Otherquenched with ice cold water
2. 2
   Extractionextracted with Et2O (3×100 ml)
3. 3
   DryingThe organic layer was dried over MgSO4
4. 4
   Concentrationconcentrated in vacuo
5. 5
   Otherpurified by column chromatography (silica, 10% EtOAc-hexane)

Procedure

To a cold mixture (0° C.) of 209 g (200 mmol) of chromium trioxide, 100 ml (1.06 mol) of acetic anhydride and 200 ml (3.5 mol) of acetic acid was added a solution of 10 g (41.8 mmol) of 6-bromo-l,2,3,4-tetrahydro-1,1-dimethylnaphthalene (Compound F) in 125 ml of benzene. The reaction mixture was stirred for 1 hour, quenched with ice cold water and extracted with Et2O (3×100 ml). The organic layer was dried over MgSO4, concentrated in vacuo, and purified by column chromatography (silica, 10% EtOAc-hexane) to give the title compound as a white solid.

Source