Pyrans are an important class of six-membered heterocyclic compounds, non-aromatic rings, composed of five carbon atoms and one oxygen atom, and contain two double bonds. The molecular formula of pyran is C5H6O, and there are two isomers. Pyrans, together with benzo derivatives, form scaffolds for a variety of drug applications, many of which are approved and promising candidates in clinical trials and recently isolated bioactive natural products.
Fluorene is a polycyclic aromatic hydrocarbon insoluble in water and soluble in many organic solvents. Fluorenes are one of the most important fluorescent molecules with applications in polymers, electronic devices, sensors, and photochromic materials.
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