DDQ-Mediated Oxidation of Allylarenes: Expedient Access to Cinnamaldehyde-Containing Phenylpropanoids

Phenylpropanoid natural products containing a cinnamaldehyde motif were easily synthesized from allylarenes mediated by 2,3-di-chloro-5,6-dicyano-1,4-benzoquinone (DDQ) oxidation. Representative examples described herein are five types of 4-hydroxycinnamaldehyde derivatives from monolignols biosynthesis, Boropinal C, and 7-methoxywutaifuranal from plant extracts. Especially, simple synthesis of 7methoxywutaifuranal was exploited through selective mono-oxidation and subsequent isomerization-ring-closing-metathesis strategy.