Recherches sur la formation et les transformations des esters XXXIII. Etude du mécanisme de la scission alcaline des monoesters phosphoriques à l'aide de H 2 18 O

By use of H 2 [ 18 O] the alkaline hydrolysis of propargyl‐phosphoric acid CHCCH 2 OPO 3 H 2 (which cannot undergo splitting by β‐elimination: no H on the β carbon atom) is shown to proceed mainly by splitting of the OP bond. As far as this fact may be extended to the alkaline hydrolysis of monoalkyl‐phosphoric acids in general, the use of H 2 [ 18 O] allows to distinguish true alkaline hydrolysis (yielding marked phosphate) from splitting by β‐elimination (yielding unmarked phosphate). β‐Elimination is generally much faster than true hydrolysis.