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

Participants

Reaction Steps

A solution of 3-ethoxy-2-cyclopenten-1-one (5 g, 0.89 mol) in THF (70 mL) was added at room temperature to a solution of 2M benzyl magnesium chloride (800 mL) under N2 and stirred for 6 h. The resulting mixture was poured into a solution of 30% H2SO4 and stirred for 5 h. The resulting organic layer was separated, and the aqueous layer was extracted with several portions of ether. The combined organic layer was dried (MgSO4), and concentrated in vacuo to give the title compound (3.1 g, 35%) as a colorless oil. NMR(CDCl3):3.45(s, 2H, benzylic protons), 5.83 (bs, 1H, olefinic proton), 7.22 (m, 5H, aromatic protons).

Provenance & Evidence