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.

pyrrolo[2,3-d]pyrimidine - isonucleoside - regioselective deprotection - triflate - cesium carbonate

一系列新颖1'-的ö -α甲基异核苷掺入与1,2,3,5-四-被有效和立体选择性地合成ö乙酰基d -ribofuranose作为起始原料。关键步骤包括在C2处对2,4-二氯苄基进行区域选择性和立体选择性脱保护，三氟甲磺酸酯化以及使用碳酸铯作为碱被适当的核碱基取代。除去残留的2，4-二氯苄基并随后转化，得到标题化合物，总产率为30-37％。产物代表具有1'- O-取代的新型异核苷。

吡咯并[2,3- d ]嘧啶-异核苷-区域选择性脱保护-三氟甲磺酸酯-碳酸铯