ABSTRACT
Citral (Figure 1) is a molecule with two double bonds and a carbonyl group, displaying a complex behavior upon hydrogenation: many intermediates and endproducts - not to speak about the optical isomers - are formed during a typical hydrogenation experiment (1, 2). Citral can be used in the preparation of citronellol (refered as OL hereafter) or citronellal (refered as AL hereafter), to be utilized by the perfume industry etc. due to their pleasant aroma (Figure 2). Acoustic irradiation has been found to enhance heterogeneous catalysis in many cases (3, 4). In hydrogenation of various organic species, Ra-Ni is an often used catalyst. Raney nickel often performs quite well, in terms of both activity and selectivity. However, the deactivation is generally quite notable. Therefore, we tried to apply this technique for two sample systems in hope of retarded catalyst deactivation.
