The self‐complementary guanosine‐ and cytidine‐derived aminomethylene‐linked C*[n]G dinucleoside 9 was synthesized by reductive amination of aldehyde 3 with an iminophosphorane derived from azide 7. Deacylation of 9 gave the isopropylidene‐protected dinucleoside 10. The sequence‐isomeric G*[n]C dinucleoside 11 was similarly prepared from aldehyde 8 and azide 5, and deacylated to 12. The association
自互补
鸟嘌呤和
胞苷衍生的
氨基亚甲基连接的C * [ n ] G二核苷9是通过用
叠氮化物7衍生的亚
氨基
磷烷对醛3进行还原胺化而合成的。9的脱酰得到异丙基保护的二核苷10。类似地,由醛8和
叠氮化物5制备了序列异构的G * [ n ] C二核苷11,并脱酰为12。CHCl 3或CHCl 3中10和12的缔合/
DMSO混合物和缔合物的结构通过1 H-NMR,ESI-MS,CD和蒸气压渗透压(VPO)进行了研究。宽1二核苷的H-NMR的信号10和12证据双链体和四链之间的平衡(Hoogsteen碱基基地之间配对沃森克里克碱基配对的双链体)。在-50°和室温之间,G * [ n ] C二核苷12的四链体占主导地位。序列异构体C * [ n ] G 10在CDCl 3和CDCl 3 /(D 6中,大部分仅形成环状双链体。
DMSO 9:1。