The molecular and crystal structure of (+/-)-1-methyl-7-oxa-norborn-5-ene-2exo,3exo-dicarboxylic acid-anhydride and its enantiodifferentiation in 1H NMR spectroscopy.

The Diels-Alder reaction between 2-methylfuran and maleic anhydride leads to the formation of known racemic title adduct 3. The structure of this compound was confirmed by X-ray crystallography. An efficient enantiodifferentiation of 3 in 1H NMR spectroscopy was observed upon treatment with Eu(hfc)3.