and Zn(OTf)2 failed to cleave the ring of BCB 1a even the reaction time was extended to 24 hours (entries 6-9). The utilization of In(OTf)3 and AgOTf gave inferior outcomes (<5% yield, 23% yield) (entries 11-12). Consequently, BF3•Et2O demonstrated optimal reactivity. Subsequently, other solvents were also examined, but lower yields of 3a were obtained (entries 13-17), ultimately highlighting toluene as the preeminent solvent. Furthermore, the slow addition of 1a to the reaction mixture gave a comparable result (Table , entry 18), while the retrieval of 2a was sustained at a 30% yield. Elevating the loading of bicyclo[1.1.0]butane 1a from 0.20 mmol to 0.30 mmol resulted in the formation of 3a with an 83% yield, accompanied by the complete conversion of 2a Upon establishing the optimized reaction conditions, an exploration of the substrate scope was undertaken. First, various BCBs 1 were reacted with benzofuran-derived oxadiene 2a. As summarized in Table