FORMATION OF AN (ALPHA-PYRONE)FE(CO)3 COMPLEX IN THE REACTION OF A TERT-BUTYL-SUBSTITUTED (ALKYNYLCARBENE)IRON(0) COMPLEX WITH CYCLOHEXADIENE

Abstract

(Eta4-alpha-pyrone)Fe(CO)3 complexes (2) are formed in the reactions of [(3,3-dimethylbutynyl)ethozymeth-ylene]Fe(CO)4 (1a) with 1,3-cyclohexadiene, 1,3-cycloheptadiene, and cycloheptatriene under CO pressure. However, an (eta4-vinylketene)iron complex (3) is formed as the major product in the reaction of [((trimethylsilyl)-ethynyl)ethoxymethylene]Fe(CO)4 (1b) with cyclohexadiene.