Photoredox-Mediated Radical Addition/Cyclization To Construct Benzannulated 6,5-Spiroketal Glycosides

We herein present a green and mild photoredox strategy for constructing a framework of benzannulated 6,5-spiroketal glycosides. This method employs various O -arylacetylene glycosides and aryl ketone acids as the starting materials, facilitating the rapid and straightforward synthesis of 6,5-spiroketal glycosides with up to 92% yields under photoredox catalytic conditions. This efficient approach has the potential to significantly enhance the molecular library of carbohydrate-based pharmaceuticals.