Total Syntheses of 4′,6′-Dimethoxy-2'-Hydroxy-3′,5′-Dimethylchalcone Derivatives

Chalcone derivatives afford several pharmacological activities. However, a general synthetic method for 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) derivatives has not been reported thus far. To address this, the preparation of 4',6'-dimethoxy-2'-hydroxy-3',5'-dimethylchalcone (MDMC) derivatives, modified compounds of DMC, in excellent overall yields is reported herein. These compounds have recently attracted growing attention due to their various pharmacological activities. Di-O-methyl-dimethylphloroacetophenone, the key intermediate containing the B-ring moiety, was fabricated by four efficient reaction steps from commercially available phloroglucinol in a 50.1% isolated yield overall. Our synthetic route, which constructs the chalcone skeleton in the final stage via a Claisen-Schmidt condensation of the key intermediate with the desired benzaldehyde derivative, can rapidly produce a vast library of DMC derivatives.