
TY  - JOUR
A1  - Dyall, LK 
T1  - Mass-Spectra of Annelated 4H-3,1-Oxazin-4-ones
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1989
VL  - 42
IS  - 10
SP  - 1813
EP  - 1818
KW  - 
UR  - https://doi.org/10.1071/CH9891813 
N2  - Electron-impact fragmentation of 2-R-4H-3,1-benzoxazin-4-ones involves primary losses of CO2 and R; there is also loss of ketene when R is methyl. The ion RCO+ is a major daughter. Successive losses of CO2and RCN yield an ion m/z 76 formulated as dehydrobenzene radical cation. In the case of 2-methyl-4H-3,1-naphth[2,3-d]oxazin-4-one, the 2,3-dehydronaphthalene ion is produced efficiently, and linked scans (B/E) were used to demonstrate that it loses C4H2 ( diacetylene ) in a retro Diels-Alder reaction. 
ER  -

