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

Novel C-27 and C-29 3-isopropyl alkanes have been unambiguously identified in sediments from the Kimmeridge Clay Formation through synthesis of a C-29 standard. The covarying concentrations and similar stable carbon isotopic compositions of C-21 and C-23 n-alkanes, C-25 and C-27 iso alkanes, and C-27 and C-29 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. Copyright (C) 1998 Elsevier Science Ltd.