Complexes of terpenes with transition metals. Part I. The reactions of cis- and trans-ocimene and of myrcene with palladium(II)

Abstract

Treatment of cis- or trans-ocimene with disodium tetrachloropalladate in methanol gives the π-allylpalladium(II) complex of geranyl methyl ether. In acetone solution, cis-ocimene is inverted to trans-ocimene, cyclised to limonene, and dimerised to a palladium(II)-complex of a C₂₀-terpene dimer. Under similar conditions in methanol, myrcene is cyclised to bis{chloro-[1,α,β-trihapto-3-(1-methoxy-1-methylethyl)-1-vinylcyclopentane] palladium-(II)} but in acetone solution it gives the palladium(II)-complex of a C₂₀-dimer. The dimers appear to be derived from a head-to-head C₁₀–C₁₀ diterpene.