Maity, Prantik and Zabel, Manfred and Koenig, Burkhard (2007) Tetrahydrofuran C alpha-tetrasubstituted amino acids: Two consecutive beta-turns in a crystalline linear tripeptide. JOURNAL OF ORGANIC CHEMISTRY, 72 (21). pp. 8046-8053. ISSN 0022-3263,
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[GRAPHICS] The synthesis of tetrahydrofuran C alpha-tetrasubstituted amino acids (TAAs) and their effect on the conformation in small peptides are reported. The synthesis starts from the protein amino acid methionine, which is protected at the C and N terminus and converted into the corresponding sulfonium salt by alkylation. Simple base treatment in the presence of an aryl aldehyde leads to the formation of tetrahydrofuran tetrasubstituted C alpha-amino acids in a highly diastereoselective (trans/cis ratio up to 97:3) reaction with moderate to good yields (35-78%) depending on the aldehyde used. Palladium-catalyzed coupling reactions allow a subsequent further functionalization of the TAA. The R,S,S-TAA-Ala dipeptide amide adopts a beta-turn type I conformation, whereas its S,R,S isomer does not. The R,S,S-Gly-TAA-Ala tripeptide amide shows in the solid state and in solution a conformation of two consecutive beta-turn type III structures, stabilized by i + 3 -> i intramolecular hydrogen bonds.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | IN-SITU GENERATION; ASYMMETRIC EPOXIDATION; AQUEOUS-SOLUTION; OPIOID-PEPTIDES; SHEET FORMATION; CHIRAL CENTERS; SIDE-CHAINS; PROTEINS; HAIRPIN; WATER; |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Organische Chemie > Lehrstuhl Prof. Dr. Burkhard König |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 02 Dec 2020 08:04 |
| Last Modified: | 02 Dec 2020 08:04 |
| URI: | https://pred.uni-regensburg.de/id/eprint/32078 |
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