Organocatalytic Enantioselective Michael–Henry Acetalization of Glutaraldehyde and 3‐Aryl‐2‐nitroprop‐2‐enols: A Facile Entry to 3‐Oxabicyclo[3.3.1]nonan‐2‐ones with Four Consecutive Stereogenic Centers

A convenient method was developed for the enantioselective (>99 % ee ) synthesis of 3‐oxabicyclo[3.3.1]nonan‐2‐ones containing four consecutive stereogenic centers. The method comprises a cascade organocatalytic Michael–Henry acetalization–oxidation reaction of glutaraldehyde and 3‐aryl‐2‐nitroprop‐2‐enols. The structures and absolute configurations of the products were confirmed by X‐ray analysis.