DAUGHTER ION MASS-SPECTRA OF 11-PENTAFLUOROBENZYL ESTER DERIVATIVES OF 11-DEHYDROTHROMBOXANE-B2 AND 11-DEHYDROTHROMBOXANE-B3

Collisionally activated decomposition (CAD) mass spectra of the [M - C6F5CH2.]- ions of 1-methyl ester-11-pentafluorobenzyl ester-9,12,15-tris(trimethylsilyl) and 9,12,15-tris(ethyldimethylsilyl) ether derivatives of 11-dehydrothromboxane B2 are presented and discussed. The spectra are interpreted with the aid of those of a corresponding 3,3,4,4-tetradeutero compound and of an analogous derivative of 11-dehydrothromboxane B3. Proposed fragmentation pathways are based on internal consistency of data from all four compounds. The migration of a trimethylsilyl or an ethyldimethylsilyl group is the salient feature of all the CAD spectra.