7 tetradecene pentadecenes hexadecenes etc and mixtures thereof preferably the olefin has 3 to 16 carbon atoms propylene is a preferred olefin of course molecular oxygen in a pure form or air is an essential co reactant for the method of this invention the co reactant and solvent must be a compound capable of generating a carboxylate ion when it serves as a solvent these compounds may be generally described as carboxylic acids or anhydrides they may include materials such as acetic acid acetic anhydride carboxylic acids although acetic acid and acetic anhydride are the preferred solvents co reactants acetic acid is the preferred co reactant of this invention borate compounds are novel for the catalysis of olefins to olefin acetates and diacetates also called esters and diesters never having been previously discovered catalysts found to be useful in the method of this invention include alkali metal borates the alkali metal component is defined as those metals in group ia of the periodic table especially preferred borates include lithium borate and sodium borate combinations of borates are also expected to be effective for example various alkali metal borates could be combined with each other or with other borate catalysts such as transition metal borates these catalysts are much less corrosive than many of those used in other methods especially the halide systems also much smaller catalyst levels may be used they are also less expensive than many of the catalyst systems.