First total synthesis of (±)-helibisabonol A

Helibisabonol A is a new sesquiterpene with phytotoxic activity isolated from Helianthus annuus leaves. (±)-Helibisabonol A has been synthesized as an approach to the natural product in the search for new herbicide models. Herein, we report the first total synthesis for this molecule from methylhydroquinone in six steps. The key steps of this synthesis are a Fries rearrangement, a Grignard reaction and a catalytic hydrogenation. The synthesis was carried out with high yield and in an easy to scale manner.