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Carbonyl compounds containing electron-withdrawing substituents are efficiently oxidized by aqueous sodium hypochlorite in the absence of added organic solvents using microwaves.

Carbonyl compounds containing electron-withdrawing substituents are efficiently oxidized by aqueous sodium hypochlorite in the absence of added organic solvents using ultrasound agitation.

Carbonyl compounds containing electron-withdrawing substituents are efficiently oxidized by percarbonate and superoxide using ultrasound.

Sodium percarbonate has been found to be a mild and effective reagent for the oxidative cleavage of α-haloketones to carboxylic acids. Furthermore, the reactions are dramatically accelerated in the presence of ultrasound with significant enhancement in yields.

Sodium percarbonate has been found to be a mild and effective reagent for the oxidative cleavage of a-diketones to carboxylic acids

Sodium percarbonate has been found to be a mild and effective reagent for the oxidative cleavage of α-haloketones to carboxylic acids. Furthermore, the reactions are dramatically accelerated in the presence of ultrasound with significant enhancement in yields.

Carbonyl compounds containing electron-withdrawing substituents are efficiently oxidized by aqueous sodium hypochlorite in the absence of added organic solvents using microwaves.

Carbonyl compounds containing electron-withdrawing substituents are efficiently oxidized by aqueous sodium hypochlorite in the absence of added organic solvents using ultrasound agitation.

Where in the curriculum is the best place to teach experimental NMR methods that are so essential to chemists and chemistry? These authors are of the opinion that NMR must be given more than a cursory introduction involving a single experiment, and present a series of experiments.

Durch Ozonolyse der Hydroxymethylenketone (I) und (III) und anschliesende basische Hydrolyse erhalt man die Dicarbonsauren (II) und (IV).

The aerobic and hypoxic metabolism of 2-nitroanthracene (2-NA) and 9-nitroanthracene (9-NA), two components of diesel exhaust, was studied and the mutagenicities of the parent compounds and their metabolites were compared. 2-NA was metabolized by 3-methylcholanthrene-induced rat liver microsomes under aerobic conditions to 2-NA trans-5,6-dihydrodiol, 2-NA trans-7,8-dihydrodiol, 2-NA 7-keto-5,6,7,8-tetrahydro-trans-5,6-diol, 2-NA 6-keto-5,6,7,8-tetrahydro-trans-7,8-diol, 2-nitro-9,10-anthraquinone and 2-NA 5,6,7,8-tetrahydrotetrol. When incubations were conducted under hypoxic conditions, 2-aminoanthracene was produced facily. N.m.r. spectral analysis indicated that the nitro-substituent of 2-NA and all of its ring-oxidized metabolites preferentially adopted an orientation in which the nitro group was coplanar or nearly co-planar with the aromatic ring system. 2-NA and its two trans-dihydrodiol metabolites were mutagenic in Salmonella typhimurium strain TA98, both in the presence and in the absence of S9 enzymes while the two tetrahydrodiol-ketones were much less mutagenic. When assayed in strains TA98NR and TA98/1,8-DNP6, the mutagenic activities of 2-NA and the trans-7,8-dihydrodiol were decreased. 2-Aminoanthracene was mutagenic in strain TA98 only in the presence of S9 enzymes. When 2-aminoanthracene was metabolized aerobically, the corresponding trans-5,6- and 7,8-dihydrodiols were not detected. These results suggest that 2-NA can be metabolized to mutagenic products by nitroreduction and ring-oxidation followed by nitroreduction, but not nitroreduction followed by ring-oxidation. Aerobic metabolism of 9-NA produced 9-NA trans-1,2- and 3,4-dihydrodiols, while metabolism was not detected under anaerobic conditions. Previous studies indicated that 9-NA and its two metabolites were not mutagenic in TA98. The differences in the orientation of the nitro substituents in 2-NA and its ring-oxidized metabolites and in 9-NA and its metabolites can be employed to explain the strong mutagenicity of 2-NA and weak mutagenicity of 9-NA when assayed both in the absence and in the presence of S9 activation enzymes.

Reaktionsprodukte sind: (II) und (III) aus (I); (IVb), (V) und (VI) aus (IVa) (unter den gleichen Bedingungen) bzw. 3-Methoxycarbonyl-phenanthren aus Phenanthren (Ausb. 23%).