ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Selectively S-Protected Cysteine Peptides. III. Synthesis of a [Ala12]-Sheep Insulin A-Chain Octapeptides with 6-11-Disulfide RingStudying the problems of the selective sulphur protection in cysteine peptides, a octapeptide A6-13 with 6-11-disulphide ring from the [Ala12]-sheep insulin A-chain was prepared by conventional synthesis using the S-Acm and S-Dpm group. The synthesis of the octapeptide Boc-Cys(Acm)-Cys(Dpm)-Ala-Gly-Val-Cys(Acm)-Ala-Leu-OH 1 was carried out with the fragments Boc-Cys(Acm)-Cys(Dpm)-Ala-Gly-OH 4 and HCl · H-Val-Cys(Acm)-Ala-Leu-OH 8 by means of DCCI/HOOBt coupling method. Fragments 4 and 8 were synthetisized step by step without carboxyl protecting group from the carboxyterminal end using the Boc-amino protecting group. Treatment of 1 with iodine in methanol gives formation of the octapeptide 2 with 6-11 - disulphide ring. The Dpm-thiol protecting group is completely stable during this step.Mass spectra of S-Dpm and S-Acm protected compounds are discussed.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19793210516