Mutual catalytic conversions of unsubstituted furan and pyran systems

Abstract

The conversions of furan, di- and tetrahydrofuran, and di- and tetrahydropyran on a molybdenum catalyst in a hydrogen atmosphere have been investigated. The studied cyclic systems readily undergo mutual conversions at 125–215°C and also undergo a hydrogenation-dehydrogenation reaction. Expansion of the unsubstituted furan rings to pyran without the introduction into the reaction medium of components capable of generating methyl radicals are described by us for the first time.