作者:Nafizal Hossain、Neeraj Garg、Jyoti Chattopadhyaya
DOI:10.1016/s0040-4020(01)80201-5
日期:1993.1
results detailed in this paper represent the first examples of a facile synthesis of 2′,3′-dideoxy-2′,3′-didehydro-3′--branched thymidines using a three-step procedure: (1) Michael addition of the phenylthiolate to nitro-olefin, (2) Henry reaction with electron-deficient reagents, and (3) subsequently, free-radical induced elimination of phenylthio and nitro groups.
苯硫醚酸根阴离子与2',3'-二脱氧-2',3'-二氢-2'-硝基胸苷1的迈克尔加成反应,以及随后在C-3'处与各种电子不足的试剂(如甲醛,甲基乙烯基酮)的亨利反应丙烯腈产生了1-(2,3-二脱氧-3-取代的-2-硫代苯基-3-硝基-β-D-戊呋喃糖基)胸腺嘧啶4 – 12 [α-取代(主要)的各种非对映异构体混合物;β-取代(次要)],收率为29–82%。在该反应中形成的产物的立体化学清楚地表明,在非对映异构体的C3'处生成的碳负离子(1.3:1的比例,1H-NMR)优先从戊呋喃糖环的α面攻击缺电子试剂。随后,来自-3'-硝基和2'-苯硫基4,5,8和11处理时被消除与卜3 SNH和AIBN,得到2',3'-二脱氧-2',3'-二脱氢-3- ' -取代的胸苷13 - 18中79-85%的产率。本文详细介绍的结果代表了2',3'-dideoxy-2',3'-didehydro-3'-的简便