Stereoselective synthesis of 4 - substituted nucleoside derivatives

摘要

The present 4 methods of synthesis of substituted nucleoside derivatives include the process of producing a stereoisomer, and there is a problem in that the purification step which causes a decrease in yield becomes complicated. Therefore, a synthesis method which is simpler and does not produce a stereoisomer is required.The present invention provides a method for synthesizing 4 substituted substituted nucleoside intermediates represented by formula (6) comprising the following steps 1 to 3.Step 1: formula (3) the compound is used as starting material, and formula (3) is a process for obtaining a formula (4) in which a substituent is introduced in a stereoselective manner by applying a nucleophilic agent to a compound.Step 2: formula (4) hydrolysis of the compound to obtain the formula (5), andStep 3: equation (5) the compound is held under acidic conditions to obtain the compound represented by equation (6)[3]In the above formula, R1 is a protecting group of hydroxyl group, me is methyl group, and X represents a substituent.