📜L-丝氨酸,N-[(9H-芴-9-基甲氧基)羰基]-L-缬氨酰-,苯基甲基酯置于palladium On Activated Charcoal 氢气,4-甲基苯磺酸吡啶体系中,用 甲醇,N,N-二甲基甲酰胺,甲苯 用作溶剂,化学反应 15.0H,反应生成(4S)-3-[(2S)-2-[[芴甲氧羰基]氨基]-3-甲基-1-氧代丁基]-2,2-二甲基-4-恶唑烷羧酸
参考文献:Pseudo-Prolines As A Molecular Hinge: Reversible Induction Of Cis Amide Bonds Into Peptide Backbones
标题:Pseudo-Prolines As A Molecular Hinge: Reversible Induction Of Cis Amide Bonds Into Peptide Backbones
摘要:Serine,Threonine-Derived (4S)-Oxazolidine-4-Carboxylic Acid,And Cysteine-Derived (4R)-Thiazolidinecarboxylic Acid,Denoted Pseudo-Proline (Xaa[psi(R1,R2)Pro]),Serve As Structure Disrupting,Solubilizing Building Blocks In Peptide Synthesis. Variation Of The 2-C Substituents Within The Heterocyclic System Results In Different Physicochemical And Conformational Properties. NMR Studies Of A Series Of Pseudo-Proline (Psi Pro)-Containing Peptides Reveal A Pronounced Effect Of The 2-C Substituents Upon The Cis To Trans Ratio Of The Adjacent Amide Bond In Solution. 2-C Unsubstituted Systems Show A Preference Similar To That Of The Proline Residue For The Trans Form,Whereas 2,2-Dimethylated Derivatives Adopt The Cis Amide Conformation In High Content. For 2-Monosubstituted Psi Pro,The Cis-Trans Distribution Depends On The 2-C Chirality. For The 2-(S)-Diastereoisomer,Both Forms Are Similarly Populated In Solution,Whereas The 2-(R)-Epimer Adopts Preferentially The Trans Form. The Results Are Supported By Conformational Energy Calculations And Suggest That,By Tailoring The Degree Of Substitution,Pseudo-Prolines May Serve As A Temporary Proline Mimetic Or As A Hinge In Peptide Backbones.
Doi:10.1021/ja962780A