The chemistry of diamantane. Part I. Synthesis and some functionalisation reactions

Abstract

Rearrangement of the tetrahydro-derivative of the heptacyclotetradecane Binor-S in the gas phase in hydrogen chloride over a chlorinated platinum-alumina catalyst at 150° or in solution in dichloromethane containing alumin-ium chloride gives diamantane in high yields. Methods for functionalisation of diamantane have been developed. Chlorination at 0° with alum'inium chloride–acetyl chloride yields equal amounts of 1- and 4-chlorodiamantane (the so-called zonal and apical derivatives) whereas use of chlorosulphonic acid at –5° yields mainly the 1-chloro-isomer. Hydrolysis of the chlorides yields the corresponding alcohols, which are separable by chromatography over alumina. The chlorides and alcohols can be equilibrated with aluminium chloride and with concentrated sulphuric acid, respectively. Oxidation of diamantane with 96% sulphuric acid at 75° yields diamantanone, 9-hydr-oxydiamantan-3-one, and diamantane-4,9-diol. Treatment of diamantan-3-ol with 70% sulphuric acid yields a mixture of mono-ols, 9-hydroxydiamantan-3-one, diamantane-3,9-diol, and diamantane-4,9-diol.