Novel Heterospirocyclic 3-Amino-2<i>H</i>-azirines as Synthons for Heterocyclic α-Amino Acids
作者:Christoph Strässler、Anthony Linden、Heinz Heimgartner
DOI:10.1002/hlca.19970800515
日期:1997.8.11
respectively, was demonstrated (Scheme 6). The solid-state conformations of the protected tripeptides 18a-d, as well as that of the corresponding carbocyclic analogue 18e, were determined by X-ray crystallography (Figs. 1-3 and Tables 1-3). All five tripeptides adopt a β-turn conformation of type III or III′. The solvent dependence of the chemical shifts of the NH resonances (Fig. 6) suggests that there is
所述heterospirocyclic Ñ甲基Ñ苯基-2- ħ -azirin -3-胺(3-(Ñ甲基ñ -苯基氨基)-2- ħ -azirines)1A - d与四氢-2- ħ噻喃,四氢通过连续地用二异丙基酰胺锂(LDA),二氯磷酸二氯酯(DPPCI)和叠氮化钠连续处理,由相应的杂环4-甲酰胺2分别合成2 H-硫吡喃和一个N保护的哌啶环(方案4)。这些氨基叠氮基与硫代苯甲酸在CH 2 Cl中的反应2在室温下以高收率得到硫代氨基甲酰基取代的苯甲酰胺13a - d。按照'azirine / oxazolone方法的规程,在制备Z-Aib-Xaa-Aib-N(Ph)Me(18)型三肽时,将叠氮基1a-d用作杂环α-氨基酸的合成子。“:处理Z-Aib取代的具有1,得到二肽酰胺15,接着选择性水解成相应的酸16,并用2,2-二甲基-2-耦合ħ -azirin -3-胺17,得到18在再次高,产率(