Synthesis of cylindricine C and a formal synthesis of cylindricine A

This paper reports the synthesis of the alkaloid natural product (±)-cylindricine C, in addition to a formal synthesis of (±)-cylindricine A. The key step in our sequence is the (ipso) regioselective addition of an alkyl Grignard reagent to a C-2 substituted pyridinium salt to generate the dihydropyridone core of the alkaloid targets. After cyclisation to form the A and C rings of the cyclindricines the net outcome is a short (13 steps) synthesis of this natural product.