Novel anti-β-functionalized γ,δ-unsaturated amino acids via a thio–Claisen rearrangement

Abstract A significantly improved thio–Claisen rearrangement method was developed for preparing anti-β-functionalized γ,δ-unsaturated amino acids, which are extremely useful nonproteinogenic amino acids used in chemistry and biology research. The mild reaction condition successfully introduced base labile functional groups into the amino acids with excellent anti/syn selectivities.