Synthesis of diketones and ω-hydroxy ketones from methyl ketones and α,ω-diols by an [IrCl(cod)]2/PPh3/KOH system

omega-Hydroxy ketones and diketones, which are important starting materials for the synthesis of cycloalkanones and heterocyclic compounds, were prepared by the one-step reaction of methyl ketones with alpha,omega-diols under the influence of an iridium complex and a base. The selectivity of omega-hydroxy ketones and diketones could be controlled by varying the starting ratio of methyl ketones to alpha,omega-diols. For example, reaction using acetophenone (5 equiv) with respect to 1,6-hexanediol (1 equiv) in the presence of [IrCl(cod)](2), PPh3, and KOH without solvent gave 1,10-diphenyl-1,10-decanedione in almost quantitative yield, while reaction using acetophenone (1 equiv) to 1,6-hexanediol (4 equiv) led to 8-hydroxy-1-phenyl-1-octanone in 92% yield. This methodology was successfully extended to the reaction of arylacetonitriles with alpha,omega-diols leading to diaryldinitriles.