Abstract The numerous published works on reactions taking place under the influence of aluminum chloride show more and more what an important part the latter plays in organic chemistry. During recent years experiments by one of the present authors and his collaborators have shown that aluminum chloride acts as a catalyst in the thermal decomposition of complex homogeneous substances, that it lowers the temperature of the decomposition and that it makes this decomposition take place in a well-defined way. This phenomenon consists of a hydrogenation by hydrogen of the unsaturated fragments of the decomposition, where the hydrogen is removed from the condensed mass of organic material. For example, a complete series of hydrocarbons of different composition and constitution are obtained by the decomposition of such substances as cholesterol, oleic acid, and abietic acid, in addition to phytosterols (betulin). These investigations showed that the chemical nature of the hydrocarbons formed differs according to the original substance. Cholesterol, for example, yields, in addition to gaseous and easily volatile paraffins, a preponderance of benzine hydrocarbons in which cyclic forms (cyclohexane and cyclopentane derivatives) predominate. Therefore benzine from cholesterol resembles benzine from crude Caucasian oil. The properties of the hydrocarbons from the higher fractions are likewise different from those of the substances named above.
Read full abstract