Novel compounds made from the reaction of 5-vinyl-2-norbornene with carboxylic acid anhydrides in the presence of oxygen are described. The process to make these novel esters is preferably conducted at a temperature in the range from about 50.degree. to 150.degree. C. and in the presence of a catalyst. A transition metal borate catalyst is preferred. Such ester compounds are potentially useful plasticizers, lubricants, solvents and fuel additives.