A class of polysubstituted functionalized furans was synthesized efficiently starting from readily available furans involving the oxidative ring opening of the furan rings using NBS as an oxidant. The reaction proceeded through a sequence of oxidative dearomatization of the furan ring/spirocyclization/aromatization.
![diethyl 2-[(5-methylfuran-2-yl)methyl]propanedioate Structure](https://image.chemsrc.com/caspic/440/25379-01-5.png)