Chemical modification of alkene-carbon monoxide alternating copolymers

Reactions of isolated carbonyl groups in ethene/propene-carbon monoxide alternating copolymers were accomplished by acid-catalysed condensation with alkene-1,2-diols (ethane-, propane-, butane- and hexane-1,2-diols) affording alkene-dioxolane copolymers. Oximation with hydroxylamine, <i>O</...

Full description

Bibliographic Details
Main Author: Khansawai, Paveena
Published: University of Edinburgh 2000
Subjects:
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.653366
Description
Summary:Reactions of isolated carbonyl groups in ethene/propene-carbon monoxide alternating copolymers were accomplished by acid-catalysed condensation with alkene-1,2-diols (ethane-, propane-, butane- and hexane-1,2-diols) affording alkene-dioxolane copolymers. Oximation with hydroxylamine, <i>O</i>- methylhydroxylamine and <i>O</i>-benzylhydroxylamine resulted in complete conversion of the carbonyl groups to their oxime derivatives. In addition, the conversions of polyketoximes, derived from ethene/propene-carbon monoxide copolymers, to 1-acteoxyiminotrimethylene and 1-benzoxyimino-trimethylene polymers were achieved by treatment with acetic anhydride and benzoyl chloride, respectively. Reaction of 1,4-dione units in ethene/propene-carbon monoxide alternating copolymers has been investigated. Paal-Knorr reactions with aniline, benzylamine and glycine ethyl ester yielded poly(alkenepyrrole) derivatives. The conversion of the carbonyl groups in ethene/propene-carbon monoxide alternating copolymers to methoximes allowed directed a-substitution reactions to be carried out on the polymer backbone. Treatment with <i>n-</i>butyllithium followed by addition of electrophiles (e.g. iodomethane, 1-iodopropane, 1-bromobutane, benzyl bromide and allyl bromide) afforded the polymer products in which 20-38% of the a-<i>syn</i> methylene hydrogens were substituted. The <i>syn</i> selectivity of the lithiation process was established b treatment of the polymethoxime with BuLi/[<i>O</i>-<sup>2</sup>H]methanol and confirmed by the presence of deuterium signal in the <sup>2</sup>H-NMR spectrum corresponding to those observed for the model compounds. Beckmann rearrangement reactions of model compounds [2.5-bis(tosyloxyimino)hexane, 2,5-bis(mesyloxyimino)hexane and 2,5-bis(hydroxyimino)hexane] were investigated and resulted in rearrangement products: <i>N,N'</i>-ethanediyl-bis-acetamide, <i>N</i>-acetyl-b-alaninemonomethylamide and <i>N,N'</i>-dimethylsuccinamide.