Synthesis of Multisubstituted Pyridines by Heterocyclization of TosMIC Derivatives: Total Synthesis of Caerulomycins A and K

A concise synthesis of multisubstituted pyridines from α-allylic TosMIC derivatives and electrophiles is reported. The process involves a tandem heterocyclization exploiting the dual reactivity of the isocyanide group. The methodology tolerates various electrophiles, including halogen sources, and proceeds under mild conditions. Its utility is showcased in the total synthesis of caerulomycins A and K, in only five steps from TosMIC.