Synthesis of a Ketomethylene Isostere of the Fibrillating Peptide SNNFGAILSS.

The direct synthesis of a ketomethylene isostere of the fibril-forming decapeptide SNNFGAILSS is presented with the goal of understanding how small structural changes alter the ability of such peptides to recognize each other for β-sheet formation. The key synthetic step relies on a SmI2-mediated coupling of a N-tetrapeptidyl oxazolidinone with a simple acrylate followed by deprotection of the carboxylic acid and a peptide coupling step with the pentapeptide H-AILSS-NH2. [ABSTRACT FROM AUTHOR]