Study of the fragmentation pathways of dimethyl disulfide derivative of 2-methyl-1,4-pentadiene by GC/MS to locate the double bonds in substituted unsaturated compounds

An experimental study has employed to examine the loss of CH$_3$SH from the dimethyl disulfide (DMDS) derivative of 2-methyl-1,4-pentadiene (cyclic thioether). This loss is particulary important to locate the double bonds in mono, di and tri-unsaturated compounds after addition of DMDS. This work shows that the migration of a H atom in the $\beta$ or in a other position relative to the sulfur atom is possible. This result shows that this method of the location of the double bonds in unsaturated compounds is also possible when the carbon atoms in the $\beta$-position relative to the sulfur atom are substituted