(+)-(1S, 2R) and (−)-(1R, 2S)-2-aminocyclobutane-1-carboxylic acids have been prepared in> 97% ee and in 33% and 20% overall yields starting from a single, chiral, bicyclic compound perceived as a chiral uracil equivalent. Construction of the cyclobutane ring is achieved via a [2+ 2] photocycloaddition reaction of this chiral precursor with ethylene.