| abstract |
Disclosed is a method of making 5-formyl-2-furoic acid and furan- 2,5-dicarboxylic acid. The method involves the use of 5-keto-aldonic acids as intermediates, as these can be subjected to ring formation by a cyclodehydration reaction under mild conditions. The 5-formyl-2-furoic acid or carboxylic derivative thereof is subjected to oxidation so as to form furan-2,5-dicarboxylic acid. The 5-keto-aldonic acid intermediates can be obtained by isomerization of uronic acids which can be obtained from sugar beet pulp, chicory pulp, fruit peals including orange peels, or non- terrestrial sources like seaweeds. A preferred source is sugar beet pulp. |