Dihydroisobenzofuran heterocycle is a structural motif found in a number of medications with antitumour, antidiabetic, and antibacterial activities. It's also found in a slew of natural substances, most notably fungus metabolites, which have been shown to possess credible radical scavenging activity. Density functional theory studies on three different derivatives were conducted to investigate their electronic structures as well as thermochemical and kinetic behaviour against •OOH, •OH, and •OCH3 in biologically relevant solvents, with the goal of elucidating structure-activity relationships and discussing the potential role of the scaffolds as a template for new semi-synthetic antioxidants. The importance of resonance and inductive effects, and also hydrogen bonding, has been underlined, but most importantly, it has been demonstrated that all structures have considerable scavenging potential against all studied radicals, with reactions rates close to the diffusion limit.