SELECTIVE PREPARATION OF OXACYCLIC AND LINEAR PHOSPHONATES AND THE EFFECT OF DIETHYL PHOSPHONATE GROUP ON SPECTROSCOPIC DETERMINATION OF THE STRUCTURES

Abstract

The formation of either oxacyclic or linear phosphonates by alternating the synthetic condition of a single method is described. Structural identification of these two isomeric oxacyclic and linear phosphonates, 2 and 3, were performed with IR, MS, ¹H & ¹³C NMR. The ¹H & ¹³C NMR spectroscopic data (ie., the chemical shifts and coupling constants) showed that the phosphonate group was the dominant factor in the conformation of oxacyclic phosphonate, with little effect from the phenyl and p-substituted phenyl groups. The phosphonate group with two ethoxy groups hovered over the THF-ring, thus presenting a complex ¹H & ¹³C NMR spectra. The results indicated that the phenyl group stretched out and away from the THF-ring, thus exerting little electronic influence on the oxacyclic ring. For linear phosphonate 3, McLafferty rearrangements with both C = O and P = O groups were observed in mass fragmentations. Spectroscopic data provided the information for identification of these phosphonates.

Key Words:

• Selective preparation
• Spectroscopic data
• Structural identification
• 2-Aryl-2-tetrahydro-furanyl phosphonate
• γ-Ketophosphonate