MENTHYL-SUBSTITUTED ORGANO-PHOSPHORUS-COMPOUNDS. VII¹: FLUORINATED COMPOUNDS AND DERIVATIVES

Abstract

The synthesis of a series of compounds, containing the (–)-menthyl group, bonded to tri-, tetra- and penta-coordinate phosphorus is described. Specifically, the formation of (–)-menthyltetrafluorophosphorane is described, based on the oxidative addition of (–)-menthyl fluoride to phosphorus trifluoride or by the oxidation-reduction reaction between (–)-menthyldichlorophosphine and arsenic trifluoride. The hydrolysis of (–)-menthyltetrafluorophosphorane was found to proceed stepwise, with formation of (–)-menthylphosphonofluoridic acid and, and ultimately, (–)-menthylphosphonic acid. ¹H-, ¹³-, ¹⁹F- and ³¹P-NMR techniques were used to establish molecular structures of (–)-menthyl-substituted phosphorus compounds. Particular attention is drawn towards the chiral discrimination of geminal fluorine pairs in (–-)-menthyl-P(X)F₂ (X=:, O, S) compounds, giving rise to ABX spin systems in the ¹⁹F(H)- and ³¹P{H}-NMR spectra.

Key Words:

• Menthylphosphorus compounds
• phosphorus-fluorine compounds
• menthylphosphonic acid
• chirality
• NMR