Complestatin synthetic studies: the effect of the amino acid configuration on peptide backbone conformation in the common western BCD macrocycle

The synthesis and structural analysis, involving X-ray crystallographic, nuclear magnetic resonance, and computational studies of four diastereomers of the common western BCD diarylether macrocycle of the complestatins, a family of HIV entry inhibitors, has been achieved exploiting a ruthenium-promoted intramolecular SNAr reaction. The stereogenicity of the individual phenylglycines (residues C and D) results in remarkable effects on the backbone conformation.