Diastereoselective thia-[3 + 2] cyclization of acetylpyranuloses and β-oxodithioesters

Abstract

Acetylpyranuloses and β-oxodithioesters, recognized as notable electrophiles and trinucleophiles, are frequently employed in intricate cyclization reactions. Nevertheless, there is a lack of literature documenting the cyclization products derived from these two reagents. This paper unveils a base-mediated sequential Michael addition and S_N2-type cyclization reactions involving acetylpyranuloses and β-oxodithioesters. A total of 23 functionalized bicyclic molecules featuring a thieno[2,3-b] pyran scaffold have been obtained diastereoselectively in moderate to good yields. This novel method could aid in the development of new drugs and enrich the toolbox for synthesizing pharmaceuticals and natural products.