Here we report an efficient route for synthesizing strigolactones (SLs) and their derivatives. Our method relies on a palladium-catalyzed oxidative carbonylation/carbocyclization/carbonylation/alkoxylation cascade reaction, which involves the formation of three new C–C bonds and a new C–O bond while cleaving one C(sp³)–H bond in a single step. With our versatile synthetic strategy, both naturally occurring and artificial SLs were prepared.