Oxygen‐17 nuclear magnetic resonance spectral investigation of 3‐alkoxy‐trans‐3,4‐disubstituted‐thiolane 1,1‐dioxides and related compounds

The 17 O NMR spectra of 3‐alkoxythiolane 1,1‐dioxides indicate that the sulfonyl oxygens are diastereotopic but their chemical shift differences are essentially independent of the structure of the alkyl group in the alkoxy moiety. Eu(fod) 3 enhances the 17 O chemical shift differences between the diastereotopic sulfonyl oxygens in 3‐isopropoxythiolane 1,1‐dioxide and shifts both oxygens upfield. α,β‐Unsaturation deshields the sulfonyl oxygens in both five‐ and six‐membered rings.