APPARENT ABSENCE OF REVERSAL OF OXAPHOSPHETANE FORMATION IN SOME WITTIG REACTIONS

Article abstract of DOI:10.1016/S0040-4039(00)84307-5

Reversal of oxaphosphetane formation in the reaction of benzaldehyde with benzylidene(2-N,N-dimethylaminophenyl)diphenylphosphorane (1) and benzylidene(4-N,N-dimethylaminophenyl)diphenylphosphorane (2), respectively, is found not to occur in tetrahydrofuran solution.The reason for this is that the rates of dissociation of the oxaphosphetanes to stilbenes and the corresponding triarylphosphine oxide are faster than reversal to the reagents.