Involved in the biosynthesis of ring A of the aminocoumarin antibiotic clorobiocin (PubMed:12480894). Catalyzes two consecutive oxidative decarboxylations of 3-dimethylallyl-4-hydroxyphenylpyruvate (3DMA-4HPP) to yield 3-dimethylallyl-4-hydroxybenzoate (3DMA-4HB) via the 3-dimethylallyl-4-hydroxymandelic acid (3DMA-4HMA) intermediate (PubMed:12777382). 3-dimethylallyl-4-hydroxyphenylpyruvate + O2 = 3-dimethylallyl-4-hydroxymandelate + CO2 3-dimethylallyl-4-hydroxymandelate + O2 = 3-dimethylallyl-4-hydroxybenzoate + CO2 + H2O Activated by ascorbate. Antibiotic biosynthesis. Homotetramer. Cells lacking this gene are unable to produce clorobiocin. Belongs to the aldolase class II family.