Hydrogen bonding in organic synthesis. Part 8. Reactions of 2-nitropropane in the presence of tetraethylammonium fluoride. The interaction of the nitro-group with fluoride

Abstract

Fluoride ions are capable of encouraging the tautomerisation of 2-nitropropane by forming a strong hydrogen bond to the aci-hydroxy-proton. Tetraethylammonium fluoride–2-nitropropane solvates are convenient sources of the 2-nitropropane anion as demonstrated by their efficient reactions with benzyl halides (to give aldehydes and C-alkylated nitropropanes), and Michael acceptors. Prolonged exposure of 2-nitropropane to fluorides results in hydrolysis of the nitroalkane. Explanations are suggested for the previously reported transformation of nitroketones in the presence of fluorides and for the reactions of potassium fluoride with highly acidic nitro-compounds.