Chemoselective Reduction of β-Keto-esters to β-Keto-alcohols.

Chemoselective reduction of the ester group in keto-esters was studied. Treatment of potassium (or lithium) enolate anions of β-keto-esters with aluminum hydride reduced the ester group chemoselectively to give β-keto-alcohols in moderate yield. Similar reactions of γ-and δ-keto-esters were not chemoselective, yielding a mixture of the diol and the keto-alcohol.