Synthesis of 2′- and 3′-spiro-isoxazolidine derivatives of thymidine & their conversions to 2′,3′-dideoxy-2′,3′-didehydro-3′--substituted nucleosides by radical promoted fragmentation.
作者:N. Hossain、A. Papchikhin、J. Plavec、J. Chattopadhyaya
DOI:10.1016/s0040-4020(01)80209-x
日期:1993.1
report the synthesis of a new class of 2′- and 3′-spiro-nucleosides (3 – 19, 38 – 55) by the 1,3-dipolar cycloaddition reaction of 2′- or 3′-methylnitrone (2, 36 or 37) with ethyl vinyl ether and acrylonitrile. It has been also shown that the free-radical promoted deoxygenation of 3′-hydroxy group vicinal to the 2′-spiro function in the free-radical precursor 15, 17 or 19 gives a mixture of 2′,3′-dideoxy-2′
本文我们报告了一类新的2'-和3'-螺-核苷(合成3 - 19,55 - 38通过的2'-或3'-甲基硝酮(所述1,3-偶极环加成反应)2,36或37)用乙基乙烯基醚和丙烯腈。还已经表明,3'-羟基基团邻位的在自由基前体的2'-螺功能自由基促进脱氧15,17或19给出的2' -脱氧-2 3'-混合物, ',3'-二脱氢-2' -取代的胸苷(20,21,24,26,28或32)和/或2',3'-二脱氧-2'-螺-衍生物(30)。类似地,2'-羟基基团邻位的在自由基前体的3' -螺功能脱氧49,52或55给出的2的混合物',3'-二脱氧-2',3'-二脱氢-3- ' -取代的核苷(59,60或62)和/或2',3'-二脱氧-3'-螺核苷(56和57)。本文描述的结果构成了核苷螺-(1,2-异恶唑烷)衍生物的合成及其在独特的自由基裂解反应中的应用的首次报道,以得到2',3'-dideoxy-2',3'