Mass spectrometric fragmentation patterns for the syn and anti isomers of PGE2 and PGD2-methyloxime methyl esters and their analogs

A systematic study of the mass spectral fragmentation of the methyl ester-methyloxime-trimethylsilyl ether derivatives of D and E prostaglandins and selected omega-chain analogs is presented. Fragments from the omega-chain analogs are shifted the appropriate mass when compared with the parent PGD2 or PGE2. NMR data of the methyloxime methyl ester of PGE2 have permitted assignment of the syn and anti isomers (relative to the alpha chain) to the fast and slow eluting gas chromatographic peaks, respectively.