Synthesis of new 3-phenyl-2,3-dihydro-1H-pyrrolizine derivatives is ac
hieved starting from 3-amino-3-phenylpropionic acid via an iminium sal
t. The reactivity of this system is studied and the new nyl-1,2,3,4-te
trahydropyrrolo-[1,2-a]pyrazin-1-one derivatives are synthesized, via
a Beckmann's rearrangment.