TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The carbon dioxide functions as self-generating acid catalyst in situ and regenerates back to a reagent during ester synthesis. The mixture of esters includes monoesters and diesters. The alcohol is 2-6C diol. The first alcohol is 1-20C alcohol, preferably methanol, ethanol or propanol. The second alcohol is 2-12C alcohol, preferably 2-6C diol. The first ester mixture includes mono-esters or diesters of any one of methyl, furan dicarboxylate, ethyl furan dicarboxylate or propyl furan dicarboxylate. The second alcohol is at least 10-20 degrees C greater than the first alcohol. Preferred Process: The step of reacting furan dicarboxylic acid with an alcohol in carbon dioxide is performed under temperature and pressure conditions that are supercritical, critical or near-critical for at least one of the alcohol or mixture of alcohols or carbon dioxide. The synthesis is performed at 150-250 degrees C, preferably 170-230 degrees C and a pressure of 400-3000 psi, preferably 920-2500 psi. The step of reacting furan dicarboxylic acid with an alcohol in carbon dioxide is performed operational conditions at supercritical, critical or near-critical reaction temperatures and pressures for alcohol or carbondioxide. The process (P1) further comprises: reacting the mixture of esters in a second esterification reaction to regenerate the alcohol and recycling the alcohol back to react with additional furan dicarboxylic acid; and separating mono-alkyl esters from di-alkyl esters by crystallization or acid-base extraction. The operational conditions, temperatures, and pressures are modified selectively to drive the synthesis reaction toward formation of diester molecules. The operational conditions is at a reaction temperature of 160-250 degrees C and reaction pressure of 400-3000 psi. The process (P2) further comprises separating monoester from the diesters by ion exchange resin, acid-base extraction, distillation or crystallization. The process (P3) further comprises regenerating the first alcohol and recycling the first alcohol back to react with additional furan dicarboxylic acid. The first ester mixture is transesterified by base-catalyzed or enzymatic reactions. The transesterification reaction is performed at 80-90 degrees C and under reduced pressure at boiling point of the first alcohol or by using lipase enzymatic reaction, where the lipase is derived from Candida antarctica. SPECIFIC COMPOUNDS - The preparation of 6 compounds (f1) is specifically claimed e.g. furan-2,5-dicarboxylic acid monomethyl ester of formula (Ia), furan-2,5-dicarboxylic acid monoethyl ester, furan-2,5-dicarboxylic acid diethyl ester, furan-2,5-dicarboxylic acid dimethyl ester and furan-2,5-dicarboxylic acid propyl ester.    EXAMPLE - Autoclave containing 5 g 2,5-furan dicarboxylic acid and 300 ml methanol was purged with nitrogen and pressurized initially with 100 psig of carbon dioxide. The reaction mixture was heated to 180 degrees C for 5 hours. The reactor vessel was cooled. The contents of the reactor were filtered, dried and worked up to give furan-2,5-dicarboxylic acid dimethyl ester (23.4 wt.%),furan-2,5-dicarboxylic acid monomethyl ester (50.6 wt.%) and unreacted 2,5-furan dicarboxylic acid (32.8 wt.%).