An Efficient Approach for the Synthesis of 1′-O-α-Methyl Pyrrolo[2,3-d]pyrimidine Isonucleosides
作者:Qiang Xiao、Yong Ju、Yang Song、Ruchun Yang、Haixin Ding、Qi Sun
DOI:10.1055/s-0030-1259961
日期:2011.4
A series of novel 1′-O-α-methyl isonucleosides were efficiently and stereoselectively synthesized with 1,2,3,5-tetra-O-acetyl-d-ribofuranose as the starting material. The key steps include regioselective and stereoselective deprotection of the 2,4-dichlorobenzyl group at C2, triflation, and substitution with appropriate nucleobases using cesium carbonate as the base. Removal of the residual 2,4-dichlorobenzyl groups and subsequent transformation afforded the title compounds in 30-37% overall yield. The products represent a new type of isonucleosides with 1′-O-substitution.
以 1,2,3,5-四-O-乙酰基-d-呋喃核糖为起始原料,高效、立体选择性地合成了一系列新型 1′-O-δ-甲基异核苷。关键步骤包括对 C2 处的 2,4-二氯苄基进行区域选择性和立体选择性脱保护、三化反应,以及以碳酸铯为碱基用适当的核碱基取代。除去残留的 2,4-二氯苄基,然后进行转化,就得到了标题化合物,总产率为 30-37%。这些产物代表了一种具有 1′-O-取代的新型异核苷。