2-Alkyltetrahydroftirans have been prepared from C10-C18 primary alcohols. Complete characterisation of these compounds by mass spectral and NMR studies has been achieved. Ring-opening reactions of the 2-alkyltetrahydrofurans have been studied and have provided an insight into the chemistry of these compounds, highlighting differences in reactivities and reaction products compared with the parent molecule, tetrahydrofuran. The C10-C18 2-alkyltetrahydrofurans have been subjected to a variety of ring cleavage reactions involving reaction with Lewis acids and/or acyl halides to produce compounds of the type; RCH(X)CH2CH2CH2-Y and RCH(Y)CH2CH2CH2-X R = C6H29 - C14H29, X = halogen atom, Y = acyl group This work has demonstrated the ease with which these compounds may be ring opened. In some cases the reaction with the 2-alkyltetrahydrofiirans was observed to be more rapid and vigorous than with tetrahydrofuran itself. This was not always the case: The acid catalysed reaction of tetrahydrofiaran with dodecanol resulted in formation of the diether shown below, and a diester was similarly formed by the acid catalysed reaction of tetrahydrofliran with lauric acid. R0(CH2)4OR diether (R = C12H25) RCOO(CH2)4OCOR diester (R= C1H23) The analogous reactions with substituted tetrahydrofurans were slow and diether/diester yield was extremely low. Introduction of the alkyl group at position two of the tetrahydrofuran ring severely impeded the reaction. Instead the hydroxy ethers shown below were the major cyclic ether derived products. C12H25-O-CH(R)(CH2)3-OH and C12H25-O-(CH2)3CH(R)-0H. (R = C6H13) Oxidation of the 2-alkyltetrahydrofurans was readily achieved by treatment with ruthenium tetroxide and resulted in formation of the corresponding alpha-alkyl-gamma-lactones and gamma-keto acids in almost quantitative yields and RCO(CH2)2COOH (R=C6H13-C14H29).
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:750680 |
| Date | January 1996 |
| Creators | Dawes, Margaret |
| Contributors | Gunstone, F. D. |
| Publisher | University of St Andrews |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10023/15315 |
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