Expediently Scalable Synthesis and Antifungal Exploration of (+)-Yahazunol and Related Meroterpenoids

Abstract

The efficient synthesis and antifungal exploration of (+)-yahazunol and related natural products are described. Central to this strategy is the Barton decarboxylative coupling, comprising a one-pot radical decarboxylation and quinone addition cascade. The scalable synthesis of (+)-yahazunol was accomplished in five longest linear sequences (LLS) starting from commercially available and inexpensive (−)-sclareol. The divergent translational potential of (+)-yahazunol was demonstrated by the expedient preparation of (−)-zonarone, (−)-isozonarone, (−)-zonarol, (−)-isozonarol, (+)-chromazonarol, and (+)-yahazunone. This approach also enables the formal synthesis of puupehenol, puupehedione, and hongoquercin A. Antifungal evaluation was performed, and this represents the first biological profiles for (+)-yahazunone, (+)-8-O-acetylyahazunone, and (+)-8-O-acetylyahazunol. (+)-Chromazonarol and (+)-yahazunone are promising candidates against Sclerotinia scleotiorum, with EC50 values of 24.1 and 28.7 μM, respectively, demonstrating advantages over the original model (DM) and synthesized heterocyclic mimic (3a) of meroterpenoids. This will favor the establishment of a chemical repertoire in the management of different plant diseases.