Synthetic Studies on Chlorofusin: Synthesis of the Cyclic Peptide Portion

The cyclic peptide portion of chlorofusin was synthesized by condensation of the five segments, D-Ada-OTMSE, Boc-L-Orn(Cbz), Boc-L-Thr-L-Ala, L-Asn(Tr)-D-Asn(Tr)-D-Leu-OTMSE, and Boc-L-Thr-D-Leu, followed by cyclization at the amide bond between D-Ada and L-Orn.