Metal-Catalyzed Cycloisomerization Reactions of cis-4-Hydroxy-5-alkynylpyrrolidinones and cis-5-Hydroxy-6-alkynylpiperidinones:Synthesis of Furo[3,2-b]pyrroles and Furo[3,2-b]pyridines

摘要

Furo[3,2-b]pyrroles and furo[3,2-b]pyridines can be conveniently prepared in good yields from thecycloisomerization reactions of cis-4-hydroxy-5-alkynylpyrrolidinones and cis-5-hydroxy-6-alky-nylpiperidinones, respectively, using Ag(I), Pd(II)/Cu(I), or Au(I) catalysis. In one case, thecycloisomerization product was unstable and produced a furan derivative by a ring-opening reaction.