Currently, there are three main known methods for preparing 2-C-Methyl-D-ribono-1,4-lactone: The first method (Hong-Se 2, Han-Young K. Tetrahedron, 2010, 66:4307-4317) uses D-glucose as a starting material, which is isomerizes to D-fructose in the presence of ethanol, acetic acid, and dimethylamine. The crude product is then obtained through multiple steps including calcium salt formation, ion exchange, dissolution, and vacuum distillation recrystallization. This method is cumbersome and complex, making industrialization difficult. The second method (Hotchkiss David, Fleet George, Heinz Thomas, et al. WO 2007025304) uses D-fructose as a starting material, reacting it first with dibenzylamine, followed by lactone formation. After 51 hours of reaction, the yield is 13%. Although this method involves fewer steps, the reaction time is long, resulting in a lower yield. The third method (Richard S, Nary an C, Frank W. US: 7598373B2) uses D-fructose as a raw material. The process involves calcium salt formation, removal of calcium ions with CO2, pH adjustment, dehydration under reduced pressure, tetrahydrofuran extraction, vacuum distillation, and recrystallization to obtain the product. The reaction time is approximately 12 hours, with a yield of 16.9%. Compared to Method 2, this method significantly reduces the reaction time and slightly increases the yield, but the process is more complex and the operation is slightly more difficult.
2-C-Methyl-D-ribono-1,4-lactone is used in synthesis of enantiomerically pure 4-substituted riboses; also for preparing saccharinic acids and lactones via Amadori rearrangement for use as synthons toward herbicidal esters and branched nucleosides.
