13C, 31P and 1H NMR studies of chiral bis[(4R,6R)‐4,6‐dimethyl‐1, 3, 2‐dioxaphosphorinan‐2‐yloxy]alkane derivatives. Coupling between phosphorus atoms six bonds apart

Abstract 13C, 1H and 31P NMR investigations were carried out to confirm the stereochemistry of novel bis[(4R,6R)‐4,6‐dimethyl‐1,3,2‐dioxaphosphorinan‐2‐yloxy]alkanes. The 13C NMR spectra exhibited second‐order features at room temperature. Substantial coupling was found between P atoms six bonds apart. The possibility of a through‐space contribution was tested. Spatially close P atoms and the strongly electronegative P substituents (oxygen atoms) are thought to be responsible for the enhanced P… P coupling.