2,4-Disubstituted Pyrrolo[2,3-<i>d</i>]pyrimidine α-<scp>D</scp>- and β-<scp>D</scp>-Ribofuranosides Related to 7-Deazaguanosine
作者:Frank Seela、Tewfik Soulimane、Kann Mersmann、Thomas Jürgens
DOI:10.1002/hlca.19900730710
日期:1990.10.31
Nucleobase-anion glycosylation (KOH, tris[2-(2-methoxyethoxy)ethyl]amine (TDA-1), MeCN) of the pyrrolo[2,3-d]pyrimidines 4a–d with 5-O-[(1,1-dimethylethyl)dimethylsilyl]-2,3-O-(1-methylethylidene)-α-D-ribo-furanosyl chloride (5) gave the protected β-D-nucleosides 6a–d stereoselectively (Scheme 1). Contrary, the β-D-halogenose 8 yielded the corresponding α-D-nucleosides (9a and 9b) apart from minor
吡咯并[2,3- d ]嘧啶4a - d与5- O -[(1, 1-二甲基乙基)二甲基甲硅烷基] -2,3 - O-(1-甲基亚乙基)-α-D-核呋喃呋喃糖酰氯(5)立体选择得到保护的β-D-核苷6a - d(方案1)。相反,除少量的β-D-异头物外,β-D-卤代糖8产生相应的α-D-核苷(9a和9b)。去保护的核苷10a和11a被转化为4-取代的2-氨基吡咯并[2,3- d ]-嘧啶β-D-呋喃呋喃糖苷1。图10C,12,14,和16和到他们的α-d端基异构体,分别为(方案2)。从4b与5的反应中,分离出包含两个核碱基部分的糖基化产物7。