Pyrones V-The Mass Spectra and Fragmentation Mechanism of Some 3(5)-Methoxy-4-pyrones

Article abstract of DOI:10.1002/oms.1210150110

The mass spectra of methyl kojate (2-hydroxymethyl-5-methoxy-4H-pyran-4-one), two deuterated analogues and 14 related 3(5)-methoxy-4-pyrones have been studied.These compounds fragment according to a common mechanism, initiated by primary rearrangement of the molecular ion(s).Guidelines which indicate the presence of 3(5)-methoxy-4-pyrones and allow sructural determinations to be made from their mass spectra are presented.For the majority of substituents studied, the nature of the substituent has no major effect upon the fragmentation pattern; the cyano group does.The hydroxy counterparts of the above compounds are readily converted for analysis by simple methylation.