If the C=C double bond in the ester has an E configuration, then the bicyclic product (9) of
dehydrohalogenation of [gamma]-halo-[delta]-lactones 3, 5, 7 acquires a trans-configuration.
NaOH (30%) solution was used in
dehydrohalogenation of epoxy resin [31].
Two mechanisms
dehydrohalogenation molecular elimination and C-Cl bond fission are discussed.
It was found that this reaction could be reversed by first reaction of the halogenated polypyridine with 9,10-dibromoanthracene and a subsequent
dehydrohalogenation reaction with 2-methylbutenoic acid.
Thomas, "Formation of carbynoid structures by chemical
dehydrohalogenation of poly(vinylidene chloride).
Reaction of 2-bromocyclohexanone (1) 32-35] with P[Cl.sub.5] in anhydrous ether gave a mixture of chloro-compounds [26], which without further purification was subjected to
dehydrohalogenation using potassium tert-butoxide/tert-butyl alcohol to isolate pure 2 in 50% overall yield from 1.
The resulting intermediate then undergoes
dehydrohalogenation followed by reductive elimination, which regenerates the catalyst and couples the other two fragments together via a new carbon-nitrogen bond.
The chlorine content of all the epoxy polymers was in the range 0.01-0.014 mot/100 g mainly due to side reactions such as
dehydrohalogenation. (20) The secondary hydroxyl group content (hydroxyl value) was in the range of 0.26-0.30 mol/100 g, which was formed along the chain molecule after reducing the epoxy group.
This represented the evolution of trimellitate plasticizing oil, combined with the
dehydrohalogenation of the chlorinated polyethylene.
The major abiotic transformation or degradation processes include hydrolysis, oxidation-reduction,
dehydrohalogenation, and photolysis (Wolfe et al.
Various authors have reported HPTC and related chlorinated pesticides degradation by
dehydrohalogenation and dehalogenation mechanism [23 31].
In addition,
dehydrohalogenation becomes important under basic conditions [28].