ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A Comparison between Different Coupling Methods in the Synthesis of the N-terminal Nonapeptide of the Sheep Insulin-A-Chain by Fragment Condensation on a Solid SupportThe N-terminal protected nonapeptide of the sheep insulin-A-chain, benzyloxycarbonyl-glycyl-isoleucyl-valyl-γ-tert.-butyl -glutamyl-glutaminyl-S-benzylcysteinyl-S-benzylcysteinyl- alanyl-glycine-methylester, was prepared by 4 + 2 + 2 + 1 - P fragment condensations on a solid support by means of various coupling methods, and detached from the matrix by transesterification with methanol. The best results of the fragment couplings have been obtained by means of the dicyclohexylcarbodiimide/pentafluorphenol-complexNomenklatur und Abkürzungen nach den Regeln der IUPAC-IUB-Commission on Biochemical Nomenclature, J. Biol. Chem. 241, 2491 (1966) u. 247, 977 (1972); weitere Abkürzungen: HOSu = N-Hydroxysuccinimid, HOBt = N-Hydroxybenzotriazol, HOOBt = 3-Hydroxy-4-oxo-3,4-dihydro-1,2,3-benzotriazin, EEDQ = 1-Ethoxycarbonyl-2-ethoxy-1,2-dihydrochinolin, Woodwards Reagens = 2-Ethyl-7-hydroxy-1,2-benzisoxazolium-tetrafluoroborat, NEPIS = 2-Ethyl-5-phenyl-1,2-oxazolium-3′-sulfonat, DCCI = Dicyclohexylcarbodiimid, PfpOH = Pentafluorphenol, Ph3P = Triphenylphosphin, (PyS)2 = 2,2′-Dipyridyldisulfid, Z = Benzyloxycarbonyl-, Nps = o-Nitrophenylsulfenyl-, Boc = tert.-Butyloxycarbonyl-, Bzl = Benzyl-, -OMe = Methylester, -OBut = tert.-Butylester, THF = Tetrahydrofuran, DMF = Dimethylformamid, Et3N = Triethylamin, NMM = N-Methylmorpholin, TFA = Trifluoressigsäure. and by the oxidation-reduction condensation method wich 2,2′-dipyridyldisulfide and triphenylphosphine. Using dicyclohexylcarbodiimide/hydroxybenzotriazole or EEDQ the optical purity results were insufficient and the yields of the fragment condensations much smaller in comparison with the other mentioned methods.
Additional Material:
3 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19783200515
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