Controlling Crossed Claisen Products

Crossed Claisen condensations make β-dicarbonyl compounds by reacting two different esters under base-promoted conditions. These reactions can be useful in organic synthesis, but the choice of reagents strongly affects the product mix.

When both esters have α hydrogens, the reaction can give a mi...

Claisen condensation between two different esters is termed crossed Claisen condensation.

If both esters contain α hydrogens, then four different types of ꞵ-ketoesters are formed. Of these, two are self-condensation products and the other two are crossed-condensation products.

A successful crossed Claisen condensation requires at l...