Synthesis of Diketones and ω-Hydroxy Ketones from Methyl Ketones and α,ω-Diols by an [IrCl(cod)]2/PPh3/KOH System

Abstract ω-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 α,ω-diols under the influence of an iridium complex and a base. The selectivity of ω-hydroxy ketones and diketones could be controlled by varying the starting ratio of methyl ketones to α,ω-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 α,ω-diols leading to diaryldinitriles.