The Synthesis Of LeuLeuLeuLeuLeu Linear Pentapeptide

This thesis expounds the synthesis of the protected LeuLeuLeuLeuLeu linear pentapeptide and dipeptide, tripeptide and their derivatives, which are anti-tumor effective by refineing mutli-step reactions with the cheap and available compounds of L-Leucine as starting materials using the liquid-phase peptide synthesis. It is found that some compounds have certain activity in anti-tumor.the activity, synthesis and separation of cyclopeptide are described. And the new contracting reagents using the synthesis of cyclopeptides are also described in the new years. On the basis of this, we designes the reasonable way of total synthesis and separation of pentapeptide. We expounds the synthesis of peptides which are covered on the literatures in the new years. On the basis of this, an useful way of total synthesis of pentapeptide is designed with the cheap and available compounds of L-Leucine as starting materials using the method of stepwise segment joined-chain.In the prescece of DIEA, the compounds of dipeptides and tripeptides are blended at the low temperature by the liquid-phase synthesis method with THF or DCM as solvent, DCC and HOBt as contracting reagents. The yield of dipeptide is 94.5～96.7ï¼…, and the yield of tripeptide is 85.7～90.6ï¼…, Dipeptides and tripeptides are extricated protects, BOC-L-Leu-Leu-OH and L-Leu-Leu-Leu-OBzl. TFA are yielded pentapeptide, pentapeptide's yield is 45.8ï¼…We expounds the most impontant problems of extricating protects of dipeptides and tripeptides in the synthesis of pentapeptide. In this thesis, butyloxycarbonyl is used as amido's protect, extricating protects method is 20ï¼…TFA(TFA: CH₂Cl₂=1: 4, V/V).Carboxyl's protect were methyl and benzyl. The method of extricating methyl is saponification using NaOH(or KOH, LiOH) in methyl alcohol solution. The method of extricating benzhyl is catalyse oxygenation. In addition, we also depicts the synthesis of pentapeptide, pentapeptid is obtained in the prescece of Et₃N and using BOP-Cl as contracting reagents, and the condition of purification is C18 material. We confirm the structure by NMR, IR, MS and other properties.Mostly, there is no literature reference compared to upwards synthesized compounds. We purified every compounds via recrytal and chromatogram, confirmed the structure by NMR, IR, MS and other properties. The reaction conditions, reaction mechanism and spectrum data have been deeply described and discussed.