Abstract
ABSTRACT: Cycloaddition of propiolic acid with isoprene leads to 4-methyl-1,4-cyclohexadiene-1-carboxylic acid in 67% yield. Subsequent reaction of this cycloadduct with O2 catalyzed by Co(OAc)2/Mn(OAc)2 affords terephthalic acid in a one-pot, cascade oxidation in 85% yield. Beyond establishing a concise synthesis of terephthalic acid, both propiolic acid and isoprene can be synthesized from methane. A route is thus formally established for synthesis of biobased terephthalic acid using renewable methane derived from biogas.