SYNTHESIS OF HEAD-TO-TAIL CYCLIZED PEPTIDES ON SOLID SUPPORT BY FMOC CHEMISTRY

Two cyclic peptides were synthesized directly on solid support by 'head-to-tail' cyclizations. Key features are side chain attachment of an Asp residue to an amide or a hydroxy linker and orthogonal protection of the alpha-carboxyl function of this amino acid as allyl ester. Cyclization was performed with TBTU as coupling reagent. Depending on the attachment the cyclic peptides contain either an Asp or an Asn residue. The method is also applicable to Glx-containing cyclic peptides.