A New Protocol for Total Synthesis of Natural Product Frutinone A and Its Derivatives

Abstract

A new protocol for total synthesis of natural product frutinone A was accomplished in three steps by using inexpensive 2 0 -hydroxyacetophenone as starting material. The key intermediate 3-(2-chlorobenzoyl)-4-hydroxycoumarin was synthesized in one pot through Baker-Venkataraman rearrangement of 2-acetylphenyl 2-chlorobenzoate followed by introduction of methyl chloroformate under basic conditions. Then, base-promoted intramolecular nucleophilic substitution reaction of 3-(2-chlorobenzoyl)-4-hydroxycoumarin provided frutinone A in excellent yield. The synthetic route features good yield, transition metal-free and mild reaction conditions, and high tolerance for functionality, thereby allowing easy substitutions around the frutinone A core.