This compound can be obtained in two different ways: 1) By reaction of 4-oxa-5-hydroxytricyclo[5.2.1.0(2,6)]dec-8-en-3-one (I) with methyl isocyanate (II) in refluxing THF. 2) By a Diels-Alder reaction of cyclopentadiene (III) with 2-(N-methylcarbamoyloxy)-2,5-dihydrofuran-5 one (IV) in THF at 120 C in a pressure vessel.