Possible origin of acyclic (linear and isoprenoid) and tricyclic terpane methyl ketones in a Tasmanian tasmanite bitumen

The C13, C14, C18 and C19 isoprenoid methyl ketones and linear methyl ketones from C9 to C21 were identified by GC/MS in a Tasmanian tasmanite bitumen. The C13 and C18 isoprenoid ketones are proposed to be derived from phytol and the linear methyl ketones from β-oxidation of the corresponding alkanes. The C14 and C19 isoprenoid methyl ketones are proposed to be derived from oxidation of double bonds in the side chain of tricyclooctaprenol or the corresponding unsaturated hydrocarbon, tricyclooctaprenene.