synthesis of 7-deazaguanosine employing pivaloylated 2-amino-6-chloro-7-deazapurine gave 18% glycosylation yield. The less bulky isobutyryl or acetyl protected amino group directed the glycosylation toward the exocyclic amino substituent. 7-Halogenated intermediates were glycosylated followed by dehalogenation to overcome the low glycosylation yield in the synthesis of 7-deazaguanosine.
非官能化的6-
氯-7-脱氮
嘌呤与市售的1 - O-乙酰基-2,3,5-三-O-苯甲酰基-β - d-
呋喃呋喃糖(45%)进行糖基化,然后胺化和脱保护,仅得到两种形式的结核菌素脚步。应用类似的条件,采用
吡咯烷基化的2-
氨基-6-
氯-7-脱氮
嘌呤合成7-脱氮
鸟嘌呤,可以得到18%的糖基化产率。较小体积的异丁酰基或乙酰基保护的
氨基将糖基化指向环外
氨基取代基。将7-卤代中间体糖基化,然后脱卤以克服7-脱氮
鸟苷合成中低糖基化产率。