One-Pot Synthesis of Multi-Substituted 4-Pyrones by a Gold-Catalyzed Cascade of Wolff Rearrangement/[4+2] Cycloaddition/ Elimination Reactions

摘要

An efficient one-pot method is described for the synthesis of a variety of di- and trisubstituted 4-pyrones based on the gold-catalyzed cascade reactions between cyclic or acyclic diazodicarbonyl compounds and vinyl ethers. The key strategy used involves the gold-catalyzed Wolff rearrangement of diazo compounds followed by [4+2] cycloaddition and elimination. This methodology is also applied to the synthesis of tetrasubstituted 4-pyrones.