학술논문
Synthesis of the two minor isomers, δ- and ε-1,2,5,6,9,10-hexabromocyclododecane, present in commercial hexabromocyclododecane
Document Type
Article
Author
Source
Subject
*BROMINATION
*FIREPROOFING agents
*POLYSTYRENE
*DIASTEREOISOMERS
*SPECTRUM analysis
*POLYBROMINATED biphenyls
*OPTICAL isomers
*NUCLEAR magnetic resonance
*LIQUID chromatography
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Language
ISSN
0045-6535
Abstract
Hexabromocyclododecane (HBCD) is prepared commercially by bromination of cis,trans,trans-cyclododecatriene (ctt-CDT) and widely used as a flame retardant, particularly in polystyrene foams. Commercial HBCD consists largely of three diastereomers, α-, β-, and γ-HBCD, the structures of which have been known for many years. Recently, the presence in the mixture of small amounts of two minor diastereomers, δ-and ε-HBCD, has been reported. Bearing in mind the manner in which commercial HBCD is generated, it was anticipated that these components are probably formed by bromination of trans,trans,trans-cyclododecatriene (ttt-CDT), a common contaminant in commercial ctt-CDT. Indeed, when a sample of ttt-CDT was brominated it gave two products, the NMR spectra and LC/MS and GC/MS behaviour of which confirmed that they are identical to the minor components, δ-and ε-HBCD, present in commercial HBCD. [Copyright &y& Elsevier]