Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.803355
Title: On the resolution of chloronitroso compounds
Author: Naismith, William E. F.
Awarding Body: University of Glasgow
Current Institution: University of Glasgow
Date of Award: 1949
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Abstract:
In Part I of this thesis I have described the preparation of the following chloronitroso compounds:- [formula redacted] Of these, (B) and (C) are new substances, but being non-distillable blue oils, they were not investigated further. The products of photochemical decomposition of (A) have been investigated in various solvents, and the reaction mechanisms discussed. In methyl and ethyl alcohols (which can supply hydrogen atoms) the main products were, a) hydrogen chloride, b) the oxime of pinacolone, and c) formaldehyde or acetaldehyde, depending on whether methyl or ethyl alcohol was used as solvent. A rearrangement appears to take place in other solvents (such as carbon tetrachloride, benzene and ether). Asymmetric photochemical experiments were also carried out with (A) taking the decomposition in stages to 94%. Polarimetric examination of the recovered material which had been exposed to right-handed and left-handed circularly polarised light, respectively, gave the value [formula redacted]. Similar experiments with (D) taking the decomposition to 96% gave the results [formula redacted]. Partial resolutions of (A) and (D) have thus been achieved with circularly polarised light. In Part II, the preparation of four menthyl and two bornyl esters of chloronitroso acids is described. Only one of these, vis [formula redacted], was crystalline, the others being viscous blue oils, unsuitable for resolution purposes. Attempts were made to resolve the solid menthyl ester by crystallisation from various solvents, but no change in either the melting point or the specific rotation was produced. With resolution still in view, three chloronitroso acids were then synthesised: [formula redacted]. All these are blue crystalline solids, and (I) and (III) are new substances. The synthesis of (I) required eight stages of which the last five were new. An unstable quinine salt was formed by (I) in ether solution, but crystallisation of this salt from methyl acetate failed to resolve this acid. Owing to the great difficulty of preparation and the small yields of the acid obtained, further investigations were not undertaken. Attempts were then made to resolve (II) with quinine. After six crystallisations of the quinine salt from ethyl alcohol, the specific rotation had decreased from [formula redacted] and polarimetric examination of the recovered acid gave the value [formula redacted]. As the progress of the resolution appeared to be very slow, more of the quinine salt was prepared and crystallised eight times from methyl acetate. Again the decrease in the specific rotation was very slow. After the eighth crystallisation [formula redacted], but had not reached a constant value. The recovered acid exhibited the Cotton effect in the region of absorption, the maximum specific rotation being +30.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.803355  DOI: Not available
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