The present invention is directed to unsaturated or derivatized long chain (C.sub.22-C.sub.50) polyunsaturated hydrocarbons and a method of preparing the long chain hydrocarbons via electrocoupling of C.sub.12-C.sub.26 fatty acids. It has been found that soapstock is an inexpensive source of starting materials for the present method. The present invention is also directed to compositions comprising the long chain polyunsaturated hydrocarbons, which can be used as reactive diluents and modifiers in latex, epoxy, alkyd and polymer compositions. In another aspect, the present invention is directed to derivitization or ozonolysis of the long chain polyunsaturated hydrocarbons. The present method is also useful for preparing C.sub.12-26 alkyl esters and C.sub.12-26 carbon chain compounds containing a terminal olefin.