α-Bromo-β,γ-unsaturated ketenes for the synthesis of α-benzylamino-β,γ-unsaturated acids

Article abstract of DOI:10.1016/j.tetasy.2003.12.029

The synthesis of α-benzylamino-β,γ-unsaturated acids has been developed starting from α-bromo-α,β-unsaturated chlorides. Via treatment of the acyl chlorides with (R)-pantolactone in the presence of TEA, the in situ formation of the deconjugated ketenes and their direct transformation into chiral esters was performed. The substitution of bromine with benzylamine, followed by acid hydrolysis, allowed to us obtain enantiomerically enriched α-benzylamino-β,γ-unsaturated acids.