Clean Synthesis in Water: Darzens Condensation Reaction of Aromatic Aldehydes with Phenacyl Chloride

The Darzens condensation reaction of aromatic aldehydes with phenacyl chloride proceeded very efficiently in a water suspension medium in the presence of triethylbenzylammonium chloride and only trans-2, 3-epoxy-l, 3-diaryl-l-propanones were formed which can be isolated simply by filtration. The structures of these compounds were confirmed by elemental analysis, IR and 1H NMR spectra. Their configurations are in agreement with that of the same compounds reported in the literature. Compared to the classical Darzens condensation, this new method has the advantages of good yields, high stereoselectivity, low running cost inexpensive and environmentally benign procedure.