Discovery and Biomimetic Synthesis of a Phloroglucinol-Terpene Adduct Collection fromBaeckea frutescensand Its Biogenetic Origin Insight

A phloroglucinol-terpene adduct (PTA) collection consisting of twenty-four molecules featuring three skeletons was discovered fromBaeckea frutescens. Inspired by its biosynthetic hypothesis, we synthesized this PTA collection by reductive activation of stable phloroglucinol precursors into highly reactiveortho-quinone methide (o-QM) intermediates and subsequently Diels-Alder cycloaddition. We also demonstrated, for the first time, the generation process of the activeo-QM by performing dynamic NMR and HPLC-MS monitoring experiments. Moreover, the PTA collection showed significant antifeedant effect toward thePlutella xylostellalarvae.