Evoninic acid (3) is a component of a 14-membered bislactone of bioactive dihydro-b-agarofuran sesquiterpenoids. The unique structure of 3 is characterized by C2',C3'-disubstituted pyridine and vicinal C7'S,C8'S-dimethyl groups. Here we report a new synthetic route to enantiopure 3. A chiral oxazolidinone controlled the stereochemical outcome of olefin hydrogenation, establishing the absolute configuration of the C7'S-methyl group. The C7'S-stereocenter then influenced the diastereoselectivity to install the C8'S-methyl group.
NSTL
Elsevier