Pd catalyzed cross-coupling reactions of the cycloadducts from 3,5-dibromo-2-pyrone and their synthetic applications towards various mono- and polycyclic compounds

Bicylolactones from Diels–Alder (D–A) cycloadditions of 3,5-dibromo-2-pyrone can undergo various palladium catalyzed cross coupling reactions to afford a series of alkenyl, alkynyl and aryl bicyclolactones. The resulting coupled products can be readily converted into various 3-OH cyclohexenes via lactone ring openings, while those bearing dienyl units underwent highly diastereoselective D–A cycloadditions with selected dienophiles to furnish multiply functionalized polycarbocycles.