Isoprene and Rubber. Part 37. Homologous Polypranes

Abstract

Abstract According to investigations by Staudinger and Fritschi the hydrorubber obtained by the catalytic reduction of rubber at 270° is a high molecular paraffin hydrocarbon. Concurrently with this work, Pummerer and Burkard were occupied with the reduction of rubber. They describe hydrorubber as an autoöxidizable substance, an observation which has been shown to be incorrect. According to Pummerer and Koch, hydrorubber can be distilled in high vacuo without decomposition, and is a highly viscous oil having the composition (C5H10)10. The hydrorubber obtained in this way is, however, according to experiments by Staudinger and Schaal highly decomposed by cracking. Our concept of the constitution of hydrorubber and the products obtained from it by cracking is again confirmed by the preparation by Karrer, Stoll, and Stevens of two high molecular hydrocarbons with numerous methyl side chains. Like octomethyldotriacontane (G40H82) recently prepared by Karrer, hexahydrosqualene (C30H62)9 and tetramethylhexadecane (C20H42) prepared by Fischer, these new hydrocarbons are to be regarded as lower members of the series of paraffins with branched chains, whose end members are hydrorubbers. Accordingly, in this series of hydrocarbons (the polypranes), representatives from the lowest member, isopentane C5H12, to the highest member, a hydrobalata having the composition ((C5H10)700 and a molecular weight of about 50,000 are known.