Halogenomethyl ketones

Formation of pyrazines by high-temperature autoclave reaction of a-halogenomethyl ketones with ammonia. 

Halogenomethyl ketones from carboxylic acid chlorides... 

Studies of y-chymotrypsin by Segal et al and of subtilisin by Kraut et al. with chloromethyl ketone analogues of good phenylalanine polypeptide substrates have indicated further similarities in substrate binding and specificity of these enzymes. It has previously been reported that both enzymes contain a serine at the active site which is acylated by ester substrates, a histidine hydrogen-bonded to this serine which is alkylated by active-site directed halogenomethyl ketones, and an aspartate which is buried and hydrogen-bonded not only to the active-site histidine but also in each case to a further serine. 

Halogenomethyl ethers s. Chloromethyl ethers a-Halogenomethyl ketones... 

Tedder and Walton [286] reviewed the kinetics of the reactions of halogenomethyl radicals in 1967. As regards mono- and difluoromethyl radicals, most of the data given in Table 24 have been obtained since that time. The commercial availability of the corresponding ketones, difluoro-... 

Dioxepans and 4,7-dehydro-1,3-dioxepins can be conveniently prepared by allowing the appropriate diol HOCH2—A—CH2OH (A = CH2CH2 or CH=CH) to react with ketones in the presence of the dimethylformamide-methyl sulphate adduct. 2-Halogenomethyl-l,3-dioxepans have also been prepared from the first of the above diols (A = CH2CH2) by its reaction, for example, with bromoacetaldehyde diethyl acetal in the presence of acid. The... 

Halogenomethylation s. lodomethylation a-Halogenomethyleneketones s. 2-Chlorovinyl ketones Halogenomethylsilanes... 

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