Experimental and theoretical rearrangement of N-acyl-2,2- dimethylaziridines in acidic medium /MADIHA KAMOUN MHIRI a , FIRAS ABOUMESSAAD b , MOHAMED LOTFI EFRIT a , YOUSSEF ARFAOUI c, ∗ and NÉJI BESBES b - MHIRI,MADIHA KAMOUN