The important naturally occurring beta-amino acid N-Boc-ADDA is prepared following a disconnection of the C-C bond between the two E,E double bonds. The stereochemistry of the two synthons was controlled using the alkylation of chiral bromoalienes derived from naturally occurring (S)-serine and (S)-phenyllactic acid. The cupration of bromoallenes derived from (S)-serine also provides a general method for the synthesis of chiral beta-alkylated aspartic acid derivatives. (C) 1997, Elsevier Science Ltd.