Stille couplings of 3-(trimethylstannyl)-5-bromo-2-pyrone for the syntheses of 3-aryl-5-bromo-2-pyrones and their ambident dienyl characters

3-(Trimethylstannyl)-5-bromo-2-pyrone underwent facile Stille Coupling reactions with aryl halides to produce various 3-substituted 5-bromo-2-pyrones. The resulting 3-aryl-2-pyrone derivatives underwent both normal and inverse electron demand Diels Alder cycloadditions depending on the type of the dienophiles being reacted. (C) 2002 Elsevier Science Ltd. All rights reserved.