ChemInform Abstract: Peptide Synthesis by a Combination of Solid‐Phase and Solution Methods. Part 2. Synthesis of Fully Protected Peptide Fragments on 2‐Methoxy‐4‐alkoxybenzyl Alcohol Resin.

Design of Peptidomimetics That Inhibit the Association of Phosphatidylinositol 3-Kinase with Platelet-Derived Growth Factor-β Receptor and Possess Cellular Activity

“…Therefore, it was postulated and supported by modeling that the C-terminal amino acid was replaced with an alkyl chain, such as N-pentylamine (Table 1). This modification could be simply incorporated by the preparation of Ac-Tyr(Bzl)-Val-Ala on a Sasrin resin [2-methoxy-4-alkoxybenzyl alcohol (a resin highly susceptible to acidic cleavage conditions)], 40,41 which was cleaved with 1.0% trifluoroacetic acid (TFA) in dichloromethane (DCM) to yield the free carboxylate. 33 Color coding for the surfaces represents electrostatic potential: red is negative, and blue is positive.…”

“…Materials and Methods. The orthogonally protected N Rt-Boc and N R -Fmoc amino acids and the resins Wang (HMP, p-benzyloxybenzyl alcohol), 56 Rink amide, 38,39 and Sasrin 40,41 were purchased from either Bachem Bioscience, Advanced Chemtech, or Peninsula Laboratories, Inc. The unnatural amino acids N R -Fmoc-diethyl-4-phosphonomethylphenylalanine [N R -Fmoc-Pmp(OEt)2] and N R -t-Boc-diethyl-4-phosphono-(difluoromethyl)phenylalanine [N R -t-Boc-CF2Pmp(OEt)2] were prepared by previously reported methods.…”

“…Method C: For the peptidomimetic tripeptides (compounds 17-23), the tripeptide Ac-Tyr(Bzl)-Val-Ala or Ac-Tyr(Bzl)-Val-D-Ala was prepared on a Sasrin resin 40,41 (5.0 mmol of free alcohol total) in a manual shaker employing the same solidphase peptide synthesis techniques as above on a 5.0-mmol scale. After resin cleavage with 1% TFA in DCM and lyophilization, the appropriate amine (5.0 equiv) was coupled using HATU (5.0 equiv), HOAt (5.0 equiv), and NMM (5.0 equiv) in THF (6 h).…”