Nitrones 2 obtained from aldehydes 1 are used for the syn-esters 24 and 25 can be obtained by the same procedure. thesis of N-ethoxyiminium salts 3. These react with several Hydrogenolysis and ester hydrolysis afford the a-amino esters of hydrogen phosphite 4 to give the N-methyl a-amino phosphonic acids 14 as well as 26 and 27, respectively. phosphonic esters 5 to 13. The N-benzyl a-amino phosphonic