An approach to a synthetic carboxylate-binding pocket based on β-avoparcin

An approach to a macrocyclic lactam designed to bind to a carboxylate anion is described. The diaryl ether 8 was synthesised by Ullmann coupling of the protected 3-hydroxyphenylglycine derivative 7 and (E)-4-bromocinnamic acid methyl ester. Elaboration of an optically pure (R)-tyrosine synthon was achieved by transfer of electrophilic azide to the N-acyl oxazolidinone 12. The synthesis of a model system is also described.