protected diamino ester (Boc-DAB-Ot-Bu, Boc-Orn-Ot-Bu) to form unnatural glycosylamino esters. The resulting glycosylamino esters are useful building blocks for solid-phase glyco-peptide synthesis. For example, the glycosylaminoacid derived by condensation of α-D-galacto-2-deoxy-oct-3-ulopyranosonic acid with benzonitrile and DAB was used to replace serine in the potent opioid peptide sequence H 2 N-Ty
aD-Galacto-2-deoxy-oct-3-ulopyranosonic 酸、α-D-gluco-2-deoxy-oct-3-ulopyranosonic 酸和 α-L-galacto-2,8-dideoxy-oct-3-ulopyranosonic 酸可通过一锅式分子内 Ritter 反应转化为非天然糖基氨基酸。最初,吡喃酮基酸在路易斯酸促进条件下与腈(苯甲腈或乙腈)和部分保护的二氨基酯(Boc-DAB-Ot-Bu、Boc-Orn-Ot-Bu)缩合形成非天然糖基氨基酯类。生成的糖基氨基酯是固相糖肽合成的有用构建单元。例如,α-D-galacto-2-deoxy-oct-3-ulopyranosonic acid 与 benzonitrile 和 DAB 缩合衍生的糖基氨基酸被用于替换有效阿片肽序列 H 2 N-Tyr-D- 中的丝氨酸Thr-Gly-Phe-Leu-Ser-CONH
One Pot Conversion of Ketoses into Sugar β-Peptides via a Ritter Reaction
α-d-Galacto-2-deoxy-oct-3-ulopyranosonic acids can be converted into unnatural glycopeptides via a one pot intramolecular Ritter reaction. Initially, the ketopyranoside reacts under Lewis acid catalyzed conditions with a nitrile (aromatic or aliphatic) to form a glycosylimino anhydride intermediate which can be isolated. Exposure of this intermediate to simple priamary amines or amino acids produces novel sugar-β-peptides. Three different nitriles and three different amines have been used to generate 6 sugar β-peptides to demonstrate the generality of this reaction.