Preparation Of Bicyclic Ketal Skeletons With Aldehyde And Alpha-Ketone Acid Through Cascade Friedel-Crafts Reaction And Stereoselective Acetalization In One Pot

Bicyclic ketal skeletons are important structure fragments that are frequently contained in natural products. A novel tandem Friedel-Crafts reaction and subsequent stereoselective acetalization were developed with readily available aldehyde and ketone acid. The reaction proceeded smoothly in the presence of catalytic Bronsted acid and afforded the corresponding product with moderate yield and high stereoselectivity.