The enantioselective isothiourea-catalysed acylative dynamic kinetic resolution of tetra-substituted 3-hydroxyphthalide derivatives using (2S,3R)-HyperBTM (5 mol%) as the catalyst (>40 examples in total) is reported. A diverse range of anhydrides, including those derived from bioactive and pharmaceutically relevant acids, can be tolerated in this process with the origin of enantioselectivity probed using DFT analysis.