Lanostane sulfides in an immature crude oil

Tetra-n-butylammonium periodate oxidation/LiAlH4 reduction, thiourea adduction and molecular distillation were employed for the isolation of pentacyclic lanostane sulfides in an immature Chinese crude oil. The position of the sulfide bridges in the molecules was assigned by the deuterium exchange and mass spectra of the corresponding sulfones. Nickel boride desulfurization of the lanostane sulfides yielded C30 and C31 lanostanes, the structures of which were established by GC-MS with co-injection of synthetic standards. None of these lanostanes were found to be present in the oil.