Stereoselective Synthesis of 1,2‐Annulated Sugars Having Substituted Tetrahydropyran/(‐furan) Scaffolds Using the Prins‐Reaction

Abstract

Lewis acid catalyzed silyl‐Prins/alkyne‐Prins reactions are utilized for the stereoselective synthesis of 1,2‐annulated sugars having substituted tetrahydropyran (or tetrahydrofuran) scaffolds from appropriately substituted sugar derived alkenyl (or alkynyl) alcohols. These annulated molecules having stereochemical/substitution dispositions similar to those of marine toxins such as maitotoxin could act as useful building blocks for the synthesis of these natural products. Further, the utility of the silyl‐Prins reaction is extended to the synthesis of cis‐sugar fused 4H‐naptho[1,2‐b]pyran and cis‐sugar fused pyrano[3,2‐c][1]benzopyran derivatives.