Patent ID: 9376410
Filing Date: 2016-06-28
CPC Classification: C07D

Claim Text:
1. A method for synthesizing (2R)-2-deoxy-2,2-disubstituted-ribono-1,4-lactone represented by General Formula V, which is carried out by the following reaction Formula: wherein R the method comprises the steps of: 1) performing a condensation reaction between the compound represented by Formula I and the compound represented by the Formula II in the presence of a condensing agent to obtain a compound represented by Formula III, in the case that X is hydroxyl, or performing an acylation reaction between the compound represented by Formula I and the compound represented by the Formula II in the presence of an acid binding agent to obtain the compound represented by Formula III, in the case that X is halogen; 2) performing an Aldol condensation reaction between the compound represented by Formula III and (R)-(+)-2,2-dimethyl-1,3-dioxolane-4-carboxaldelyde in the presence of a Lewis acid and an organic base to obtain a compound represented by Formula IV, wherein the Lewis acid is titanium tetrachloride; and 3) performing a deprotection reaction and ring closure of the compound represented by Formula IV in an acidic system to obtain a compound represented by General Formula V, wherein the acidic system is a mixture of hydrocloric acid, sulfuric acid, acetic acid or trifluoroacetic acid and alcoholic solvent.