ɪn lˈæbɹətˌɔːɹi kaʊmˈælɪk ˈæsɪd mˈeɪ biː əbtˈeɪnd baɪ sˈɛlfkɑːndɛnsˈeɪʃən ʌv mˈælɪk ˈæsɪd ɪn fjˈuːmɪŋ sʌlfjˈʊɹɹɪk ˈæsɪd:
In laboratory coumalic acid may be obtained by self-condensation of malic acid in fuming sulfuric acid: