In this article we describe the synthesis of a β-truxinate from the [2+2] dimerization of methyl 4-nitrocinnamate and its isomerization by different bases using liquid-assisted grinding (LAG) technique. With this methodology it is possible to obtain the corresponding ζ- and δ-truxinates in short reaction times and with only small amounts of solvent. Furthermore, it is possible to steer the process towards the preferential formation of ζ- or δ-truxinate depending on the base used.