Liquid–liquid and solid–liquid phase-transfer glycosylation of pyrrolo[2,3-d]pyrimidines: stereospecific synthesis of 2-deoxy-β-<scp>D</scp>-ribofuranosides related to 2′-deoxy-7-carbaguanosine
作者:Frank Seela、Bernhard Westermann、Uwe Bindig
DOI:10.1039/p19880000697
日期:——
such as compounds (3d) or (3e) decreases side reactions to some extent. To overcome these difficulties solid–liquid phase-transfer glycosylation employing an aprotic solvent, solid KOH, and the cryptand tris[2-(2-methoxyethoxy)ethyl]amine (TDA-1) has been developed. The new glycosylation method leads stereospecifically in high yield to 2-amino-4-alkoxy-(7a–c) or 2-amino-4-chloro-7H-pyrrolo[2,3-d]pyrimidine
2-氨基-4-甲氧基-7 H-吡咯并[2,3- d ]嘧啶(3b)与2-脱氧-3,5-二-O-(对甲苯甲酰基)-的相转移糖基化的产率α- d -赤-pentofuranosyl酰氯(4)液体-液体的条件下是有限的(50%NaOH水溶液,CH 2氯2,卜4 NHSO 4)由于碱-不稳定的保护基团在halogenose的脱保护(4) 。更具亲脂性的2-氨基-4-烷氧基吡咯并[2,3- d ]嘧啶的应用,例如化合物(3d)或(3e)在某种程度上减少了副反应。为了克服这些困难,已经开发了使用非质子传递溶剂,固体KOH和穴状三[2-(2-甲氧基乙氧基)乙基]胺(TDA-1)的固液相转移糖基化技术。新的糖基化方法以立体定向的方式高产地导致了2-amino-4-alkoxy-(7a–c)或2-amino-4-chloro-7 H -pyrrolo [2,3 - d ] pyrimidine2-deoxy-β-