Structure elucidation of C_(80), C_(81) and C_(82) isoprenoid tetraacids responsible for naphthenate deposition in crude oil production

摘要

A series of C_(80) isoprenoid 20-bis-16,16'-biphytanyl tetraacids has previously been found to be responsible for calcium naphthenate scaling in crude oil processing. This paper describes the structure elucidation by high-field NMR spectroscopy of the structures of the series of homologous C_(80) tetraacids containing 4-8 five-membered rings. In addition, the structures of methyl-substituted C_(81) and C_(82) analogues containing 7 and 8 five-membered rings have been determined for the first time. The biosynthetic implications are discussed.