A facile synthesis in aqueous medium of 3-hydroxy-2-pyrone from aldaric acids or their derivatives

3-Hydroxy-2-pyrone is a valuable building block of many molecules. The syntheses until now proposed to prepare this compound are not ecofriendly and are unsuitable for large scale productions. We now report an easy gram scale preparation of this pyrone, by simple heating in water of bio-based 6-caboxylic-3-hydroxy-2-pyrone derivatives. The full process can be also performed by a telescopic reaction starting from galactaric acid (mucic acid)