Synthesis and pharmacological evaluation of enantiomerically pure <i>endo</i>-configured KOR agonists with 2-azabicyclo[3.2.1]octane scaffold
作者:Hendrik Jonas、Daniele Aiello、Bastian Frehland、Kirstin Lehmkuhl、Dirk Schepmann、Jens Köhler、Patrizia Diana、Bernhard Wünsch
DOI:10.1039/d1ob01498f
日期:——
Conformationally restricted bicyclic KOR agonists 10 with an endo-configured amino moiety were synthesized to analyze the bioactive conformation of conformationally flexible KOR agonists such as 2–5. A seven-step synthesis starting with (S)-configured 4-oxopiperidine-2-carboxylate 13 was developed. cis- and trans-configured diesters 12 were obtained in a 3 : 1 ratio via hydrogenation of the α,β-unsaturated
合成了具有内构型氨基部分的构象限制性双环 KOR 激动剂10 ,以分析构象灵活的 KOR 激动剂(例如2-5 )的生物活性构象。开发了从 ( S )-构型 4-氧代哌啶-2-羧酸酯13开始的七步合成方法。通过α,β-不饱和酯14的氢化,以3:1的比例获得顺式和反式构型的二酯12 。建立双环支架后,酮11的非对映选择性还原胺化仅提供内构型双环胺10a,b 。分别通过手性 HPLC 分离对映体的 3:1 混合物,得到对映体纯的 KOR 激动剂 (1 S ,5 S ,7 R )- 10a,b和 (1 R ,5 R ,7 S )- 10a,b ( ent - 10a,b )。 KOR 亲和力是在放射性配体 [ 3 H]U-69 593 的受体结合研究中确定的。内构胺10a ( K = 7 nM) 和10b ( K = 13 nM) 的高 KOR 亲和力表明二面角KOR药效团元素N(吡咯烷)–C–C