Synthesis of Fluorene- and Spirobifluorene-Fused Thiophenes
摘要:
A novel synthetic route to fluorene- and spirobifluorene-fused thiophenes is explored by starting with ninhydrin. The Die Is-Alder cycloaddition was employed to construct the key intermediate, 2,3-bis(hydroxymethyl)-1,4-diphenyl-fluorenone, which was further converted stepwise to the target molecules. All of dihydrothiophenes and final products are confirmed by H-1 NMR, C-13 NMR and mass spectrometry.