‘One-pot’ four-step synthesis of cerpegin

Cerpegin (1) was synthesized through a ‘one-pot’ reaction in 71% overall yield. Lithiation of commercially available 2-methoxynicotinic acid (2) as its lithium salt using LTMP, followed by addition of acetone at low temperature and a specific acidic treatment of the intermediate 3 thus obtained, gave the 1,1-dimethyl-3,4-dioxo-1,3,4,5-tetrahydrofuro[3,4-c]pyridine (4). The latter was finally selectively alkylated using methyl iodide and caesium carbonate to afford cerpegin (1).