Chemistry - How to synthesize cyclopentane from cyclohexane?

Solution 1:

Why not just use the Aldol condensation on the dialdehyde produced from ozonolysis and save some steps?

Solution 2:

Your route looks good until the last step. After decarboxylation, the intermediate will be cyclopentanone. So all that will be left to do is reduce the ketone to an alkane (you probably know a couple of options).

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Solution 3:

I know this is an old thread that only just became back to life so it's probably no longer worth it, but I'd think you could shorten these routes a bit by using some ring-contraction chemistry (e.g. Favorskii):

Refs: 1. M. T. Musser, Cyclohexanol and cyclohexanone. Ullmann's Encycloedia of industrial chemistry, 2000. 2. Synth. Comm. 2007, 37, 4149. 3. JACS 1960, 82, 4307. 4. J. Chem. Soc., Chem. Commun. 1983, 939.