Gt. Whiteker et al., DIRECT NMR OBSERVATION OF ATROPISOMERISM OF A BISPHOSPHITE DIBENZO[D,F][1,3,2]DIOXAPHOSPHEPIN MOIETY, Journal of the Chemical Society, Chemical Communications, (17), 1995, pp. 1805-1806
Rapid interconversion of two diastereoisomeric bisphosphite ligands by
dibenzo[d,f][1,3,2]dioxaphosphepin epimerization has been observed by
variable temperature H-1 NMR.