Mass Spectrometry of Chromen-2-ones (Coumarins) and of Furo- and Pyrano-chromenones

Mass Spectrometry Study of Coumarins: Correlation Between Charges of Atoms and Fragmentation Processes

“…The process with carbonyl loss has been described several times for coumarins [28,29] and for isocoumarins. [30,31] So has the contraction of the cycle of oxygenated fused heterocycles [22,26,32] or phenol derivatives.…”

Low‐energy collision‐induced dissociation tandem mass spectrometry of 7‐acetonyloxycoumarins

“…However, the methoxy‐substituted compounds ( 11 , 16 , 17 , 18 and 22 ) did not show this neutral loss at all. This is an interesting finding since the CO loss is very common in the EI spectra of many coumarins . The reason for the preferential CO loss for compound 9 is not known, however.…”

“…This is an interesting finding since the CO loss is very common in the EI spectra of many coumarins. [11] The reason for the preferential CO loss for compound 9 is not known, however. The obvious mechanism for this loss is a simple elimination of the ring carbonyl leading to a furanyl-type (cyclic ether) structure.…”

“…For example, methoxy‐substituted coumarins gave rise to abundant CH 3 ● and CH 3 O ● eliminations. An extensive review on EI‐MS studies of coumarins was published by Vulf'son and Golovkina, which stated that the nature of substituents has a decisive influence on the fragmentation, sometimes greatly deactivating CO elimination channels. It was also observed that positional isomers could also be differentiated.…”

Naturally occurring oxygen-ring compounds

“…"~ A number of new simple oxygenated"6 and g l u c o s i d i~'~~ xanthones have been reported. Two xanthones, kayeaxanthone (74) and (75), have been isolated from the timber of Kayea stylosa,"* and the revised structure for toxyloxanthone B has been c~nfirmed. "~ / OMe…”