Evidence of the loss of chirality at the phosphonium step in the arbuzov rearrangement

Article abstract of DOI:10.1016/S0040-4039(00)97643-3

Reaction of the diastereomerically pure oxazaphospholidine 3 with alkyl halides was monitored by ¹H, ¹³C, ³¹P NMR and clearly showed the formation of two phosphonium intermediates with the same diastereomeric ratio as that of the final products. Benzyl halides reacted with 3 yielding a mixture of the two epimers a and b which syncrystallized into a rare addition compound.