Dibenzo-1,4-dioxane dioxin

Diode array-UVD (DA-UVD) 953 1,3,2-Dioxaborins, formation of 683 Dioxanes—see 1,3-Benzodioxanes Dioxepens—see Dibenzodioxepens Dioxins—see Dibenzo-p-dioxins Dioxiranes, as oxidants 1255, 1257, 1258 Dioxocines—see Dibenzodioxocines Dioxygen-copper complexes, as oxidants 1194, 1198... 

The reaction of iV-(2,4-dinitrophenyl)amino acids with base in aqueous dioxane has been shown to give benzimidazole iV-oxides (7). The rate-determining step is likely to be formation of an iV-alkylidene-2-nitrosoaniline intermediate (6), which is followed by rapid cyclization and decarboxylation.19 The loss of carbon dioxide from perbenzoate anions has been investigated by mass spectrometry and electronic structure calculations. The results, including isotopic labelling experiments, support a mechanism involving initial intramolecular nucleophilic attack at either the ortho- or ipso-ring positions. They also indicate that epoxides may be intermediates en route to the phenoxide products.20 There has also been a theoretical study of the formation of trichlorinated dibenzo-/ -dioxins by reaction of 2,4,5-trichlorophenolate ions with 2,4-dichlorophenol.21... 

Phase-transfer catalysis in the chemistry of 1,3-dioxanes 92MI8. Polychlorinated dibenzo-/ -dioxines 91CLY158. 

Dioxin is a common name for dibenzo-l,4-dioxane, which is 1,4-dioxane fused with two benzene rings. The name dioxin is often used incorrectly in the news media for 2,3,7,8-tetrachlorodibenzodioxin (TCDD), a toxic contaminant in the synthesis of the herbicide called 2,4,5-T or Agent Orange. Surprisingly, TCDD has been in the environment for many millions of years because it is also formed in forest fires. Most dioxins are toxic and carcinogenic (cause cancer) because they associate with DNA and cause a misreading of the genetic code. 

R)-Spirobi-1,4-dioxan (212) has been prepared from 2-chloro-ethyl 3-D-fructopyranoside.220 A study of the half-chair conformations of compounds (213 X and Y = or S or S02 R1, R2=a variety of substituents or benzo) has been made using H n.m.r. spectros-copy,221 and the conformation of dibenzo-1,4-dioxin is folded about the 0-0 axis at an angle of 16S3 according to an n.m.r. study.222 Tetrachlorodibenzodioxin is a very stable compound but electrolysis in the presence of other oxidizable compounds breaks down the molecule.22 3... 

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