f R', R and R' is a --COOH radical, and(ii) when either R and R' is a phenyl or an inertly-substituted phenyl radical, the other is neither a phenyl or an inertly-substituted phenyl radical;with a decarboxylation catalyst of the formulawhereM is a combination of copper and molbydenum;M' is at least one of sodium, potassium, cesium, tin and bismuth;a is a number of about 0.1 to 1;b is a number