Palladium-catalysed synthesis of 3- and 4-substituted 2H-pyran-2-ones

Palladium(O)-catalysed cross-coupling reactions of 4-methoxy-6-methyl-3-chlorozinco-2-pyrone with aryl- and vinyl-halides and 4-bromo-2-pyrone with organozinc compounds such as aryl-, heteroaryl- and ethynyl-zinc chlorides produce 3- and 4-substituted 2H-pyran-2-ones in moderate to good yields.