Structure and significance of a novel rearranged monoaromatic steroid hydrocarbon in petroleum
A monoaromatic steroid hydrocarbon isolated from a catalytic dehydrogenation/isomerization mixture derived from 5..cap alpha..-cholestane was determined to be a (10..beta.. ..-->.. 5..beta..) CH/sub 3/-rearranged monoaromatic steroid (2a) by /sup 1/HNMR analysis. Gas chromatography-mass spectrometry (GCMS) coinjection with a crude oil monoaromatic fraction and GCMS elution patterns suggest that this 5..beta..-Me rearranged monoaromatic steroid is part of a series of C/sub 27/-C/sub 29/ homologues in 20S and 20R pairs (2a-f) which are found in nearly all crude oils. Evidence from a study of Toarcian sediments from West Germany shows that the relative amounts of rearranged (2a-f) compared to regular (1a-1) C-ring monoaromatic steroids depends upon the strength of the anoxic environment during sedimentation. In addition, observation of rearranged/regular MA-steroid ratios in a suite of Jurassic oils demonstrates the differential effects of maturation on the preservation of the two series of biomarker compounds.
- Research Organization:
- Chevron Oil Field Research Co., Richmond, CA
- OSTI ID:
- 6930948
- Journal Information:
- Geochim. Cosmochim. Acta; (United States), Journal Name: Geochim. Cosmochim. Acta; (United States) Vol. 50:3; ISSN GCACA
- Country of Publication:
- United States
- Language:
- English
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