Catalytic Enantioselective Total Synthesis of (+)-Torrubiellone C

Silyl-protected (R)-methyl 2-(hydroxymethyl)butanoate was obtained by an enantioselective Ir-catalyzed hydrogenation in high yield and selectivity. Elaboration of this building block via Takai and Stille reactions gave a protected hydroxy polyene chain, which was coupled to a 5-hydroxyphenyl-4-hydroxy-2-pyridone derivative by a modified Horner–Wadsworth–Emmons reaction. Deprotection gave synthetic (+)-torrubiellone C, which led to the assignment of the configuration of the natural product as (R).