Enantiomeric Syntheses of Conformationally Restricted <scp>d</scp>- and <scp>l</scp>-2‘,3‘-Dideoxy-2‘,3‘-<i>endo</i>-methylene Nucleosides from Carbohydrate Chiral Templates
作者:Byoung K. Chun、Sureyya Olgen、Joon H. Hong、M. Gary Newton、Chung K. Chu
DOI:10.1021/jo991212l
日期:2000.2.1
3-dideoxy-2, 3-endo-methylenepentofuranosyl acetates (21 and 34, respectively) or the chlorides 22 and 35. The acetates and chlorides were condensed with pyrimidine and purine bases by Vorbrüggen conditions or S(N)2-type condensation. Vorbrüggen conditions using the acetates gave mostly alpha-isomers. In contrast, S(N)2-type condensation using the chlorides greatly improved the beta/alpha ratio. From
合成了D-和L-2',3'-二脱氧-2',3'-内-亚甲基核苷作为潜在的抗病毒剂。通过选择性保护D-和L-2获得关键中间体5-O-叔丁基二苯基甲硅烷基-D-和L-2,3-dideoxy-2、3-内-亚甲基五呋喃糖酶(分别为20和33),分别由1,2:5,6-二-O-异亚丙基-D-甘露醇和L-古洛糖伽马内酯制得的3-dideoxy-2,3-endo-methylpentose衍生物19和32转化为5 -O-叔丁基二苯基甲硅烷基-D-和L-2,3-二脱氧-2,3-内-亚甲基五呋喃糖基乙酸酯(分别为21和34)或氯化物22和35。乙酸盐和氯化物与嘧啶和嘌呤缩合在Vorbrüggen条件下产生碱或S(N)2型缩合反应。使用乙酸盐的福布吕根条件主要产生α-异构体。相反,使用氯化物的S(N)2型缩合大大提高了beta / alpha比率。通过合成,获得了几种D-和L-2',3'-二脱氧-2',3'-内