Abstract: A process for preparing esters and halides is disclosed comprising the step of reacting a cyclic olefin having the formula I ##STR1## wherein R.sub.1 and R.sub.4 are the same or different from each other and each represents hydrogen, methyl, or ethyl;R.sub.2 and R.sub.3 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms; andn represents a whole number from 2 to 12, with an acyclic olefin having the formula II ##STR2## wherein R.sub.5 represents hydrogen, methyl, ethyl or the group ##STR3## wherein R.sub.12 and R.sub.13 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms;Y represents halogen; an acyloxy group R.sub.14 --CO--O wherein R.sub.14 represents alkyl containing 1-12 carbon atoms, phenyl or phenyl alkyl containing 7-12 carbon atoms, or an oxycarbonyl group R.sub.15 --O--CO wherein R.sub.