LARGE RATE ENHANCEMENT FOR THE HYDROLYSIS OF A 4-MEMBERED RING PHOSPHONAMIDATE

Unlike beta-lactams a four-membered cyclic 1,2-azaphosphetidine shows enhanced hydrolytic reactivity compared with an acyclic analogue; the cyclic phosphonamidate 3 undergoes hydroxide-ion catalysed hydrolysis in water with endocyclic P-N fission; a corresponding acyclic derivati ve hydrolyses with P-O fission in basic solution, the rate difference between the cyclic and acyclic structures for P-N fission is greater t han 5 x 10(8).