Preparation of b-Keto Esters Using Mesoporous Silica Catalyst

Significance

Aluminum-MCM-41 was found to promote the reaction of aldehydes and diazo­esters. Thus, the cation-exchange reaction of a mesoporous silica-ammonium composite with Al(III) in water followed by calcinative removal of the organic cations gave the Al-MCM-41 catalyst. Al-MCM-41 catalyzed the reaction of heptanal with ethyl diazoacetate in CH₂Cl₂ to give β-keto ester 2 in 99% yield. The catalyst was readily recovered by simple filtration and reused three times without any loss of catalytic activity.