Chemoselective hydrogenation of unsaturated ketones in the presence of copper catalysts

Chemoselective hydrogenation of the open chain unsatd. ketones geranylacetone, 6-methyl-5-hepten-2-one, and 5-hexen-2-one was achieved in the presence of supported copper catalysts by using 2-propanol as hydrogen donor or as a solvent. The support and reaction conditions were modified to obtain highly selective transformation. In particular, the use of Cu/SiO2 catalyst in 2-propanol, under N2 or H2, allowed the chemoselective redn. of the carbonyl group in geranylacetone. In hydrocarbon solvent, the reaction can be addressed towards the one pot synthesis of valuable ethers.