The catalysed synthesis of symmetrical ketones from alcohols

Reaction of a series of primary and secondary alcohols (1-propanol, 2-propa nol, 1-butanol, 2-methyl-1-propanol, 1-pentanol, 1-hexanol and 1-heptanol) with O-2 over CeO2/MgO (1 atm, 450 degreesC) produced the symmetrical keton e with 2n-1 carbon atoms in 5-45% yield. The ketones were characterised by a combination of GC-MS and H-1 NMR spectroscopy. Aldehydes and aldol conden sation products were the main products produced in competing reactions. No ketone was produced from the reaction of 2-methyl-2-propanol with oxygen. R eaction of a 1:I mixture of 1-hexanol and 1-heptanol over the CeO2/MgO cata lyst produced a statistical yield of the three expected ketones. The data a re consistent with oxidation of the alcohol to the acid followed by couplin g of two acid molecules to give the symmetrical ketone. (C) 2001 Elsevier S cience B.V. All rights reserved.