摘要:
Halogenation of 4-aroyl(arylsulfonyl)oxyimino-2,5-cyclohexadienones is not accompanied by change of the configuration at the nitrogen atom. p-Benzoquinone oxime ethers and esters take up halogens in a regioselective fashion at the syn-C=C bond of the quinoid ring. The main factor responsible for regioselective addition of halogens is configuration at the nitrogen atom, which determines the stability of intermediate halogenonium ion.