Carbonyliron Complexation and Carbonyl Insertion of Allenic Ketones

Abstract

The allenic alpha-ketones 5a-f give, on irradiation in the presence of [Fe(CO)5], the bis(tricarbonyliron) complexes 6a-f. In the case of ketone 5e, a minor bis(tricarbonyliron) complex with the proposed unique structure 8 is also obtained. Ketones 5a-d, which are disubstituted at C(4), under the same conditions, afford also the lactones 7a-d in moderate yields. The latter reaction is a new carbonyliron-mediated carbonyl insertion. The structure of the binuclear complexes 1a and 6e were established by X-ray crystallography.