Hydrochloric Acid → 3-Benzylcyclopent-2-en-1-one

Participants

Reaction Conditions

Reaction Steps

To a −78° C. solution of benzyl magnesium chloride (14.3 mL, 28.5 mmol, 1.2 eq, 2 M solution in THF) in ether (50 mL) was slowly added 3-ethoxycyclopent-2-enone (2.84 mL, 23.8 mmol, 1 eq.). The reaction mixture was warmed up to −30° C. over 1 hour. At this point, a 1 M solution of HCl was added to the reaction mixture until the pH was adjusted to 1 as indicated by litmus paper. The solution was warmed up to room temperature and the layers were separated. The aqueous phase was extracted with 40 mL of Et2O (3×) and the combined organic layers were washed with 100 mL of brine (1×), dried over anhydrous MgSO4 and concentrated in vacuo. The residual oil was purified by flash chromatography (25% EtOAc/hexanes) to give (3.1 g, 76% yield) of the title compound as a colorless oil.

Provenance & Evidence