Skeletal Rearrangements of More Complex Molecules

From the above discussion, it ensues that a number of reactions involving carbon-carbon bond rupture and formation may be accounted for by a limited number of adsorbed species and elementary steps. The predominant precursor species in skeletal rearrangements are metallocyclobutanes and metallocarbenes, which can be further dehydrogenated to metallocarbynes. 

On account of the variety of reactions that are initiated by these very reactive species, the chemistry of large molecules may become extremely complex. As a matter of fact, each compound may constitute a specific case. The nature of the predominant reactions depends primarily upon the structure of the reactant, and of course, upon the catalyst. 

Product Distributions from 1,1,3- and 1,1,2-Trimethylcyclopentanes on Metal Films  

The results from a careful study (139) of the reactions of a number of polymethylcycloalkanes (10-16) on cobalt films in the presence of deuterium at 100°-215°C may be summarized as follows  

Exchange and cracking of 14 are about twice as fast as of 13, showing the stabilizing effect of gemdimethyl groups. 

---