Synthesis of a new enantiopure bicyclic γ/δ-amino acid (BTKa) derived from tartaric acid and α-amino acetophenone

The synthesis of a novel enantiopure γ/δ-amino acid having the 3-aza-6,8-dioxabicyclo[3.2.1]octane structure was realized by the combination of tartaric acid derivatives and α-amino acetophenone followed by a trans-acetalisation process. This amino acid, which has a rigid skeleton and carries substituents at the 3, 5 and 7 positions of the scaffold, could find different applications in organic and peptidomimetic synthesis. Two different synthetic strategies were studied, one of them allowing the multigram scale preparation of the amino acid.