EnantiopureN-and/or C-protectedhomo-β-aminoacids are prepared readily and in good yields from N-protected α-aminoacids with the same side chain, via reduction of the carboxyl function and conversion of the resulting N-protected β-amino alcohol into the corresponding β-amino iodide and then β-amino cyanide. The key step of this strategy is represented by the synthesis of the enantiopure N-protected