The Creighton process involves the hydrogenation of a 6 carbon chain alcohol. The reactant is 2,3,4,5,6-pentahydroxyhexanal (an aldehyde. The product is 1,2,3,4,5,6-hexanehexol (an alcohol; compare with ethylene glycol and glycerol. The product has two more hydrogen atoms than the reactant: -CHO is replaced by -CH2OH.[1]
The Creighton process was patented in the 1920s. For details, please see the external link.