Volatile Components of the Thermal Degradation of 2,5-Dimethyl-4-hydroxy-3(2H)-furanone

2,5-Dimethyl-4-hydroxy-3(2H)-furanone or DMHF was subjected to a roasting temperature of 160 °C for 30 min in a closed system at various pH values (2.2, 5.1, and 7.1). The yield of the total volatiles generated decreased with increasing pH value, indicating that degradations occurred more readily at a lower pH. Generally, the volatiles identified were acyclic carbonyls and 3(2H)-furanone derivatives, with furanone production favored at the higher pH values. Formation of the described products implies that during thermal degradations in water, DMHF undergoes ring opening and hydrolysis first, then, by a retroaldolization, produces the primary degradations products which react in an intermolecular fashion to form the secondary products. Possible formation mechanisms for the products are postulated.