Metal carbonyl chemistry. Part XXV. Reactions of acetyl- and benzoyl-pentacarbonylmanganese with dicyclopentadiene

Abstract

Dicyclopentadiene reacts with [(RCO)Mn(CO)₅](R = Me or Ph) in hexane or benzene to give the known 1 : 1 adduct [(RCO·C₁₀H₁₂)Mn(CO)₄] as the major product, with low yields of the 2 : 1 adduct [(RCO·C₁₀H₁₂)Mn(CO)₄-(C₁₀H₁₂)] and a novel lactone [(C₁₀H₁₂·[graphic omitted]R)Mn(CO)₄(C₁₀H₁₂)]. When the reaction between [(MeCO)Mn-(CO)₅] and the diene is carried out in acetonitrile the lactone is one of the major products. An acyl derivative of a similar lactone complex, namely, [(C₁₀H₁₂·[graphic omitted]Me)CO·Mn(CO)₅] is obtained when the 1 : 1 adduct (R = Me) is carbonylated. The formation of these various products is discussed and compared with the formation of the lactone complexes [([graphic omitted]Me)Mn(CO)₅] and [([graphic omitted]Me)CO·Mn(CO)₅] from reaction between CH₃·CO·CH₂·CH₂·COCl and Na[Mn(CO)₅].