On the synthesis of pyrylium salts

Abstract

Abstract The present work is on the synthesis of a pyrylium salt, 8-hydroxy-2,4-diphenyl-5,6,7,8-tetrahydrochromenylium tetrafluoroborate, a precursor for interesting transition metal ligands. Different routes are presented with the aim of making an affordable precursor for the variety of syntheses possible from these versatile pyrylium salts. New findings include a preparative non optimized 2-hydroxy – cyclohexanone synthesis. It includes high resolution measurements not found in literature for several substrates.

Keywords

Triphenylpyrilium, 8-oxo-2,4-diphenyl-5,6,7,8- tetrahydrobenzopyrylium tetrafluoroborate, Ichiis reagent, CBS reductions, oxygen insertions, DIBAL reductions, singlet oxygen, Magtrieve™ oxidation, Oxone™ oxidations, manganese oxidation, Oppenauer and Meerwein Schmidt Ponndorf Verley transfer hydrogenations.