Activation and carbonylation of methylcyclopentane in HF-SbF5

Activation and carbonylation of methylcyclopentane with carbon monoxide in HF-SbF5 was investigated. The relative importance of the various activation pathways of the alkane is discussed on the basis of the material balance in the product distribution. Protolysis of the tertiary C-H bond as monitored by hydrogen production depends on the strength of the superacid, and the selectivity of the carbonylation depends very much on the experimental procedure. A good selectivity in cyclic esters can only be obtained by sacrificing a large amount of the starting material as a hydride donor.