Boron tribromide → 6-Hydroxy-7-methyl-1,2,3,4-tetrahydronaphthalen-1-one

Participants

Reaction Conditions

Reaction Steps

A solution of 2.79 g (14.7 mmol) of 6-methoxy-7-methyl-1,2,3,4-tetrahydro-1-naphthalenone in 150 mL of CH2Cl2 was cooled in ice and treated with 20 mL (0.22 mol) of BBr3. After stirring at 0° C. for 0.5 hour, the solution was stirred at room temperature overnight. The solution was poured into ice water and extracted with Et2O. The Et2O was extracted twice with 5% NaOH and the NaOH washed with Et2O. The NaOH solution was acidified to the Congo Red end point with dilute HCl, then extracted with Et2O. The Et2O was washed with saturated NaCl and dried over MgSO4. Removal of the solvent under reduced pressure left the crude product. This was taken up in acetone and treated with charcoal. Filtering through Celite and removal of the solvent under reduced pressure left 2.08 g (80.6% yield) of the product as a brown solid. The structure was confirmed by NMR and mass spectroscopy. MS m/z 177 (M+H+).

Provenance & Evidence