The First Asymmetric Intramolecular <i>Stetter</i> Reaction. Preliminary Communication

Abstract

Abstract The first asymmetric intramolecular Stetter reaction is reported, using the chiral triazolium salt 1 as catalyst. Starting from the easily accessible 4‐(2‐formylphenoxy)but‐2‐enoates 2 , this protocol opens up an enantioselective pathway to the benzo‐annulated pyran‐4‐ones (chroman‐4‐ones) 3a–h with good yields and enantiomeric excesses of up to 74%.