The invention relates to a process for production of at least one C4 oxidation product, comprising the steps: a) providing a feed composition comprising at least two feed compounds selected from tert-butyl alcohol, methyl tert-butyl ether and isobutylene; b) subjecting the feed composition to a catalytic reaction zone comprising at least one oxidation stage and obtaining a reaction phase comprising the C4 oxidation product, to a C4 oxidation product obtainable therefrom, to an apparatus for production of at least one C4 oxidation product, a process carried out in the apparatus, to a methacrylic acid, to a polymer comprising methacrylic acid and process for production thereof, to methyl methacrylate and a process for production thereof, to a methacrylate ester and a process for production thereof, to a polymer comprising at least one of methacrylic acid, methyl methacrylate and a methacrylate ester and a process for production thereof, to a composition comprising at least one of methacrylic acid, methyl methacrylate, a methacrylate ester and a polymer comprising at least one of methacrylic acid, methyl methacrylate and a methacrylate ester, to chemical products, and to the use of at least one of methacrylic acid, methyl methacrylate, a methacrylate ester, a polymer comprising at least one of methacrylic acid, methyl methacrylate and a methacrylate ester and a composition comprising at least one of these in chemical products.