Tetrahydropyran is an organic compound consisting of a saturated six-membered ring containing five carbon atoms and one oxygen atom. Tetrahydropyrans are common structural motifs in natural products and synthetic therapeutic molecules. In nature, these six-membered oxygen heterocycles are usually assembled by intramolecular reactions, including oxygen Michael addition or ring opening of epoxy alcohols. In fact, polyether natural products have been particularly extensively studied for their fascinating structures and important biological properties; these are often formed through endoselective epoxy open cascades.
In addition to the nitrogen-based heterocycles presented so far, a number of others nitrogen-based scaffolds have also been reported as promising agents for GBM treatment, including pyrazolo-triazole, imidazotetrazine, piperidine, purine, imidazopyrazine, pyrazole, triazole among others.