Total Synthesis of Onitin.

The total synthesis of the phenolic sesquiterpene onitin using dimethylated indanone as the key intermediate is reported. Key to the success of this synthesis route is the Suzuki-Miyaura cross-coupling reaction of aryl bromide to introduce the vinyl side chain followed by formyl selective Wacker oxidation to generate the aldehyde. The target aldehyde was also obtained in high overall yield via an acid-catalyzed pinacol-pinacolone-type rearrangement of the epoxide. The epoxide was generated from oxidation of a styrene derivative by oxone. Demethylation of the aldehyde followed by chemoselective reduction furnished onitin.