合成路线1

Title compound was synthesized by solid phase peptide synthesis on a Wang resin using N-9-fluorenylmethoxycarbonyl (Fmoc)-protected amino acids. The (Fmoc)alanine-resin (I) was treated with piperidine in N-methylpyrrolidone to yield deprotected alanine-resin (II). Then, condensation with (Fmoc)-phenylalanine (III) using diisopropyl cabodiimide (DIC) and 1-hydroxybenzotriazole (HOBt) as the coupling reagents provided the (Fmoc)-dipeptide resin (IV), which was deprotected as before with piperidine in NMP. The resulting deprotected dipeptide resin (V) was submitted to further sequential amino acid coupling and deprotection cycles with (Fmoc)-phenylalanine (III), (Fmoc)-valine (VII), and (Fmoc)-leucine (IX), to yield in turn resins (VI), (VIII), and (X), respectively. Resin (X) was then coupled with cholic acid (XI) in the presence of DIC and HOBt to give the corresponding amide (XII).