MASS SPECTRA OF GRISEOFULVIN ANALOGUES . CHARACTERISTIC FRAGMENTATION PROCESSES IN MASS SPECTRA OF SPIROCYCLOHEXENONES AND SPIRO-CYCLOHEXANONES CONTAINING GRISEOFULVIN SKELETON

The mass spectra of a number of griseofulvin analogues have been examined and the fragmentations, which are characteristic of the basic skeleton of the molecule, have been determined. In all of the different structural types examined, the ring cleavages which predominate are found tol occur by fission of one or more of the bonds attached to the spiro carbon atom. The degree of unsaturation in the spiro‐cyclohexane ring system is found to controll the type of fragmentation which occurs and the type of ring system which is present can therefore be identified by its mass spectrum. Copyright © 1969 John Wiley & Sons, Ltd.