Dimethyl-hydroxyacetone

After cleavage the reaction mass is a mixture of phenol, acetone, and a variety of other products such as cumylphenols, acetophenone, dimethyl-phenylcarbinol, a-methylstyrene, and hydroxyacetone. It may be neutralised with a sodium phenoxide solution (20) or other suitable base or ion-exchange resins. Process water may be added to facilitate removal of any inorganic salts. The product may then go through a separation and a wash stage, or go direcdy to a distillation tower. 

Since the enolization is not restricted to the 2 and 3 positions, a number of products are formed that undergo subsequent aldol condensations and the Cannizzaro oxidation. They are all 2-hydroxy-3-methyl, 3,4-dimethyl-2-hydroxy, 3,5-dimethyl-2-hydroxy, and 3-ethyl-2-hydroxy-2-cyclopenten-l-ones sugar acids acetic acid hydroxyacetone three isomeric hydroxy-2-butanones y-butyrolactone and such furan derivatives as furyl alcohol, 5-methyl-2-furyl alcohol, and 2,5-dimethyl-4-hydroxy-3(2H)-furanone. They are food flavoring agents. 

An important compound is 4-hydroxy-5-methyl-2H-furan-3-one, known as norfuraneol. Norfuraneol occurs in caramel, roasted chicory root and also in meat broth. 4-Hydroxy-2,5-dimethyl-2H-furan-3-one, known as furaneol, strawberry furanone or pineapple furanone, arises in the Maillard reaction from L-rhamnose (Figure 4.39) and in a reaction of methylglyoxal with hydroxyacetone (Figure 4.41). It occurs, for example, in strawberries, pineapple, roasted almonds, popcorn, meat broth and a number of other foods as a racemic mixture. The structure of (+)-(J )-furaneol responsible for the characteristic odour is given in formula 8-160. The odour of furaneol is sugary, jammy and reminiscent of strawberries and, at higher concentrations, caramel (threshold concentration is... 

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