Carbon‐13 NMR Studies of 3‐Aryl‐4‐(5‐aryl‐Δ ²‐1,2,4‐oxadiazolin‐3‐yl)sydnones and 3‐Aryl‐4‐(5‐aryl‐1,2,4‐oxadiazol‐3‐yl)sydnones

Abstract

The 13C NMR spectra of twelve 3‐aryl‐4‐(5‐aryl‐Δ2‐l,2,4‐oxadiazolin‐3‐yl)sydnones and twelve 3‐aryl‐4‐(5‐aryl‐l,2,4‐oxadiazol‐3‐yl)sydnones have been measured and assigned by means of proton‐noise decoupling and DEPT‐experiments. The coupling constants were determined by means of gated decoupling, and NOE effects were observed by comparison of proton‐decoupled and inverse‐gated decoupled spectra. Differences shown by the oxadiazoline and the oxadiazole rings and the substitution effects are discussed.