The Xanthate Route to Amino Acids.

The degenerative xanthate addition transfer to alkenes allows the synthesis of a broad range of protected, and in some cases enantiopure, α, β, and γ-amino acids, including proline and pipecolic derivatives, as well as fluorinated congeners and β-lactams. The radical addition furnishes naturally latent mercapto-α-amino acids that are ideally equipped for native chemical ligation. Most of the amino acid structures accessible rapidly by this chemistry would otherwise require tedious multi-step syntheses.