Complexing of terpenes with transition metals. Part V. Reactions of 3,7-dimethylocta-1,6-diene and of 7-methoxy-3,7-dimethyloct-1-ene with rhodium(III) and thallium(III)

Abstract

3,7-Dimethylocta-1,6-diene and 7-methoxy-3,7-dimethyloct-1-ene are catalytically oxidised at the vinyl group by RhCl₃–FeCl₃ in oxygen to the derived methyl ketones in good yield. An accompanying alkene isomerisation reaction (–CMe·CH:CH₂→–CMe:CH·CH₃) has been studied. The above octadiene and methoxyoctene are hydroformylated (–CMe·CH:CH₂→–CMe·CH₂·CH₂·CHO) in good yield by [RhH(CO)(PPh₃)₃], with some accompanying alkene isomerisation.

With Tl(NO₃)₃, 3,7-dimethylocta-1,6-diene reacts at the 6,7-double bond to give a ketone with migration of a methyl group, and at the 1,2-double bond with cyclisation to give cyclopentane derivatives.