One-bond C–H NMR coupling constants in 1,2,4-trioxanes: a reversed perlin effect

Abstract

In a reversal of the Perlin effect, the values of 1JC–H for the equatorial protons at C(3) and C(6) in 1,2,4-trioxanes are less than those for the corresponding axial protons; this is ascribed to homoanomeric interactions between equatorially directed nonbonding electron pairs on oxygen and the equatorial C(3)–H or C(6)–H σ* orbitals.