a-Chloro-a'-(dibenzylamino) methylketones 3 are synthesized in enantiomerically pure form starting from a-amino acids. Reduction of amino ketones 3 and further epoxidation affords threo aminoalkyl epoxides 6 with diastereoisomeric excess ranging between 94% and 98%. The synthesis of erythro amino epoxides 9 is also described by reaction of a-amino aldehydes 7 with in situ generated (halomethy1) lithium. Amino epoxides 9 were obtained ...