Coumarins with terpene and tert‐butyl substituents were synthesized via Pechmann condensation reaction. New derivatives were investigated in different model system for the exhibition of antioxidant, radical scavenging and membrane‐protective activities. It has been found that 4‐methylcoumarin derivatives with monoterpene moieties exhibit high antioxidant activities. The most active and promising for further investigations is 5‐hydroxy‐6,8‐diisobornyl‐4‐methylcoumarin, containing two isobornyl substituents on the benzopyran ring.