To reduce the NOx and soot emissions of conventional diesel fuels, different renewable alternatives are investigated. One example are oxymethylene ethers (OMEx) of different chain lengths, which are intended to be used as diesel blends. Especially OME3-5 show properties comparable to diesel. The key to producing longer chain OMEs is OME1 as feedstock, which can react with formaldehyde to afford larger molecules. This article reviews different synthesis routes for OME1, in order to elucidate energy-efficient methods.