Two efficient methods have been developed for the synthesis of variously substituted 2‐aminomethylazetidine derivatives 5 by regioselective nucleophilic substitution of 4‐mesyloxymethylazetidin‐2‐ones 3 followed by reduction or by reduction of the appropriate 4‐oxo‐azetidine‐2‐carboxamides 7 . A novel ring transformation of 4‐oxoazetidine‐2‐carboxamides 7 into tetrahydroquinolines 16 by reaction with lithium aluminium hydride/aluminium trichloride has been investigated.