EXTENDED 8,14-SECOHOPANES IN SOME SEEP OILS FROM PAKISTAN

An alkane fraction isolated from Pakistani oil seep samples using liqu id chromatography on US-Y molecular sieves has been shown to contain s ix pseudohomologous series of tetracyclic compounds that have mass spe ctral characteristics of 8,14-secohopanes with carbon numbers extendin g to 35. This is the first report of extended 8,14-secohopanes in a cr ude oil, although extended 8,14-secohopanes with up to 32 carbon atoms have previously been reported from a Chinese coal of Jurassic age. Th e Kovats indices of these extended 8,14-secohopanes are reported from measurements using capillary gas chromatography columns with nonpolar and polar stationary phases.