Long-chain 3-isopropyl alkanes : a new class of sedimentary acyclic hydrocarbons

Abstract

Novel C27 and C29 3-isopropyl alkanes have been unambiguously identified in sediments from the Kimmeridge Clay Formation through synthesis of a C29 standard. The covarying concentrations and similar stable carbon isotopic compositions of C21 and C23 n-alkanes, C25 and C27 iso alkanes, and C27 and C29 3-isopropyl alkanes suggest a common, though unknown, biological source. It may be that these compounds are all products of an unknown biosynthetic process ultimately leading to the formation of isopropyl alkanes.