Synthesis of a New Class of Functionalized Isoxazole/Isoxazoline Styrylchromone Derivatives

A simple and practical method of synthesis of a new series of functionalized isoxazole/isoxazoline styrylchromone derivatives from 3-hydroxy-2-styrylchromone via an alkene/alkyne-tethered intermediate by adopting intermolecular 1,3-dipolar cycloaddition of nitrile oxide in the presence of the environmentally safe sodium hypochloride oxidant under mild reaction conditions. The structures of all the synthesized compounds were confirmed by ¹H and ¹³C NMR, ESI–MS, and ESI-HRMS.