Intramolecular Diels-Alder cycloadditions of 2-pyrones toward the synthesis of medium sized macrocyclic skeletons

초록

Synthesis of medium-sized macrolactones via an intramolecular Diels-Alder (IMDA) reaction of 2-pyrone containing alkyne tether occurs with remarkably high diastereofacial as well as endo/exo selectivity. Because of the ring strain in the alkyne-tethered, medium-sized ring system, single methyl group provides sufficient steric bias leading to the formation of single diastereomeric medium-sized macrolactones.