Bio‐Based Building Blocks in Organic Synthesis: Access to Tetrahydropyran‐Fused Carbocycles via Levoglucosenone and Cyrene Platforms

The tetrahydropyran (THP) skeleton is a key structural element of δ‐lactols and δ‐lactones, which, in combination with the carbocyclic framework, form the basis of many biologically active natural compounds. Given the prevalence of such bicyclic systems in molecules with diverse pharmacological properties, effective strategies for constructing this core are of great importance for organic and medicinal chemistry. In this study, we established a synthesis based on cellulose‐derived platform chemicals—levoglucosenone and its hydrogenated derivative Cyrene. These renewable chiral building blocks facilitate the transformation of biomass into advanced functionalized intermediates. We explored two primary pathways: metathesis and the aldol condensation of 1,5‐dicarbonyl compounds. Intramolecular cyclization with SmI 2 unexpectedly led to the formation of new carbocyclic structures. All obtained functionalized scaffolds serve as valuable precursors for the synthesis of biologically active compounds.