Cycloheptatriene and tropylium metal complexes. Part VI. Tropone and alkoxycycloheptatriene complexes of tricarbonylchromium

Abstract

Tropone and alkoxycycloheptatrienes react with tris(acetonitrile)tricarbonylchromium to give the corresponding tricarbonylchromium complexes. endo-Alkoxycycloheptatriene complexes so formed suffer hydride abstraction by triphenylmethyl tetrafluoroborate giving alkoxytropylium complexes which can be hydrolysed to the tropone complex. The latter is readily protonated or alkylated on oxygen but is unreactive towards most nucleophiles. Grignard and organolithium compounds cause its partial ring contraction to benzenetricarbonylchromium.