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Madden, Raymond Walter (1954) Degree of retention of optical rotatory power in replacement reactions. Doctoral thesis, Northern Polytechnic.
The interaction of an alcohol and a hydrogen halide appears to involve the rapid protonisation of the alcohol, ROH + HC1→ ROH2+ Cl, followed by dehydration of the oxonium entity giving rise to alkyl halide by a mechanism not yet quite clear, but probably to some extent by the inversion mechanism, Cl→ROH2+ → RC1 + H2O. influence of product water has been recognised as of considerable importance, and in previous kinetic studies, attempts have been made to neutralise its effect. In the present work attention has been given to the study of the protonisation process, especially to determine the amount of hydrogen halide absorbed by an alcohol, according to the structure of the alcohol. Furthermore, the extraction of hydrogen chloride from the entity, ROH2+ Cl, by water has been examined to give further information about the influence of product water. Results of this investigation are discussed. The second stage of the overall process leading to alkyl halide has been studied by long and short term experiments at different temperatures. It is now shown that the Initial amount of hydrogen chloride can be enhanced in several ways, and this has a marked effect in increasing the yield of alkyl halide. Thionyl halide - alcohol and phosphorus trihalide - alcohol systems have been studied also, the whole investigation being directed to the discovering of the cause of loss (in certain cases small) in rotatory power when an optically active alcohol is converted into the alkyl halide. Some useful progress has been made.
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