Aspects of mass spectra of organic compounds. Part III. Synthesis and mass spectrum of 4-methylfuro(3′,2′ :3,4)coumarin
Abstract
The furocoumarin (II) and its [2-13C]analogue have been prepared. Despite the similarity of the mass spectra of this coumarin (II) and the corresponding pyronocoumarin (I), energy measurements have shown that initial fragmentation of the pyronocoumarin (I) leads to a partly open-chain ion (V), and not to the corresponding cyclic ion (II).