Abstract: | The mass spectra of morellin and other related natural products, isolated from the various Garcinia species, have been recorded and the data has been rationalised. The characteristic cleavage is the opening of the bicyclo(2.2.2) octenone ring system by a retro-Diels-Alder reaction. The γ-pyrone ring also undergoes the retro-Diels-Alder fragmentation. These two modes of cleavage indicate the different substituents on the main skeleton of morellin. The hydrogenated derivatives show slight variations in their fragmentation modes. The mass spectral data assists considerably in the structural elucidation of similar complex molecules, if isolated in minute quantities. |