Enantiopure unnatural homologated amino acids, whereby there is > 1 carbon atom between the C- and N- termini have found great utility in a number of applications. The enantiopure syntheses of β-amino acids are well documented, as increasingly are those of γ-amino acids. δ-Amino acids on the other hand are much less well-studied despite reports of their potential utility. This review attempts to summarise strategies that have been adopted towards the enantioselective synthesis of δ-amino acids and their precursors (e.g. nitrile/nitro/azido/ester/alcohol etc) and where appropriate demonstrate their utility. Only systems which are all carbon between the two termini are considered and only those where the shortest route between any given C-termini and any given N-termini is four carbons long (i.e. lysine derivatives are not considered).

对映体非天然同源氨基酸，在C-和N-末端之间有> 1个碳原子，已发现在许多应用中具有很大的用途。β-氨基酸的对映体纯合成已得到充分证明，γ-氨基酸的对映体合成也越来越多。另一方面，尽管有潜在用途的报道，但对δ-氨基酸的研究却少得多。这篇综述试图总结已被用于对映体选择性合成δ-氨基酸及其前体（例如腈/硝基/叠氮基/酯/醇等）的策略，并在适当情况下证明其实用性。仅考虑两个末端之间均为碳的系统，并且仅考虑任何给定C末端与任何给定N之间最短路径的系统-末端为四个碳原子长（即不考虑赖氨酸衍生物）。