Synthesis of natural product inulavosin via Ga(OTf)3-Catalyzed Hetero Diels-Alder Dimerization of salicyl alcohol derivative.

Inulavosin, a natural melanogenesis inhibitor, has been synthesized smoothly from readily available and inexpensive starting materials by using a Ga(OTf)3-catalyzed room temperature hetero Diels-Alder dimerization of salicyl alcohol derivative and a regioselective phenol monobromination as the key steps.