Amino Acids and Peptides. LI. Application of the 2-Adamantyloxycarbonyl (2-Adoc) Group to the Protection of the Hydoxyl Function of Tyrosine in Peptide Synthesis.
作者:Yoshio OKADA、Noriyuki SHINTOMI、Yukihiro KONDO、Toshio YOKOI、Shima JOSHI、Wei LI
DOI:10.1248/cpb.45.1860
日期:——
A 2-adamantyloxycarbonyl (2-Adoc) group was introduced as a protecting group for the hydroxyl function of tyrosine (Tyr) through the Shotten-Bauman reaction of 2-adamantyloxycarbonyl chloride with the copper complex of Tyr. The 2-Adoc group is stable to trifluoroacetic acid (TFA), 5.0 N HCl/dioxane, hydrogenation over a Pd catalyst and tertiary amine, and is easily removed by treatment with 1 M triflyoromethanesulfonic acid (TFMSA)-thioanisole/TFA and HF. Boc-Tyr(2-Adoc)-OH was prepared by the reaction of (Boc)2O and H-Tyr(2-Adoc)-OH in the presence of triethylamine. Boc-Tyr(2-Adoc)-OH was successfully applied to the synthesis of Boc-Ala-Thr-Val-Lys(2-Adoc)-Phe-Lys(2-Adoc)-Tyr(2-Adoc)-Lys(2-Adoc)-Gly-OH, corresponding to the sequence 1-9 of Sulfolobus solfataricus RNase, and Boc-Tyr(2-Adoc)-Asp(O-2-Ada)-Gly(O-cHex)-Gly-OH, corresponding to the sequence 33-36 of S. solfataricus RNase.Boc-Phe-Lys(2-Adoc)-Tyr(2-Adoc)-Lys(2-Adoc)-Gly-OBzl was treated with anhydrous HF to afford H-Phe-Lys-Tyr-Lys-Gly-OH wighout any side reactions, in a good yield.
引入了2-阿丹托氧羧基(2-Adoc)作为酪氨酸(Tyr)羟基功能的保护基团,通过2-阿丹托氧羧基氯化物与Tyr的铜络合物的肖滕-鲍曼反应来实现。2-Adoc基团对三氟乙酸(TFA),5.0 N HCl/二氧六烷,氢化(在Pd催化剂上)和叔胺是稳定的,而且可以通过1 M三氟甲烷磺酸(TFMSA)-硫醚/ TFA和HF的处理轻松去除。Boc-Tyr(2-Adoc)-OH是通过在三乙胺存在下反应(Boc)2O与H-Tyr(2-Adoc)-OH制备的。Boc-Tyr(2-Adoc)-OH成功应用于合成Boc-Ala-Thr-Val-Lys(2-Adoc)-Phe-Lys(2-Adoc)-Tyr(2-Adoc)-Lys(2-Adoc)-Gly-OH,对应于Sulfolobus solfataricus RNase的序列1-9,以及Boc-Tyr(2-Adoc)-Asp(O-2-Ada)-Gly(O-cHex)-Gly-OH,对应于S. solfataricus RNase的序列33-36。Boc-Phe-Lys(2-Adoc)-Tyr(2-Adoc)-Lys(2-Adoc)-Gly-OBzl经过无水HF处理,在没有任何副反应的情况下获得了H-Phe-Lys-Tyr-Lys-Gly-OH,且收率良好。