trans,trans-Dibenzylideneacetone often abbreviated dba, is an organic compound with the formula C17H14O. It is a pale-yellow solid insoluble in water, but soluble in ethanol.

Synthesis

trans,trans-Dibenzylideneacetone can be prepared in high yield and purity by condensation of benzaldehyde and acetone with sodium hydroxide in a water/ethanol medium followed by recrystallization.

This reaction, which proceeds via the intermediacy of benzylideneacetone, is often performed in organic chemistry classes and is called Claisen-Schmidt condensation.

Uses

trans,trans-Dibenzylideneacetone was used as an additive in the copper-catalyzed-arylation of imidazoles. It is a reactant involved in Nazarov-like cyclization, Transfer hydrogenation, Lewis acid-mediated condensation, Hetero-Diels-Alder reactions, Asymmetric 1,4-addition reactions, and Michael addition reactions.

Application

In recent years, a strong emphasis has been placed on developing catalytic methods to generate chiral cyclopropanes via Michael-initiated ring-closure reactions. In 2006, Lloyd-Jones et al. reported the asymmetric indium-mediated homoallyl-cyclopropanation reaction of dibenzylideneacetone performed in the presence of a chiral and cheap modifier such as (S)-methyl mandelate.

The reaction proceeded via stepwise cleavage of the Cdouble bondO bond and delivery of two allyl fragments from the reagent, providing the corresponding cyclopropane in high de. This cyclopropane was further submitted to a Ru-catalysed ring-closing metathesis to generate the corresponding chiral norcarene.