Six-Membered Ring Phosphates and Phosphonates As Model Compounds for Cyclic Phosphate Prodrugs: Is the Anomeric Effect Involved in the Selective and Spontaneous Cleavage of Cyclic Phosphate Prodrugs?
the P-heterocyclic ring, and particularly, the anomeric effect are involved in the spontaneous and selective cleavage of the C4−O3 bond in cyclic phosph(on)ates. We arrived at this assumption based on the conformational and configurational study of simple model phosphates and phosphonates, where it was observed that the spontaneous conversion of unstable six-membered ringphosphates to their most stable