Oxidation, of alkyl groups

Attempted simple oxidation of alkyl groups on thianthrenes would also effect 5-oxidation. However, sulfones can be side-chain-oxidized 2,3,6,7-tetramethyl-, 1,2,7,8-tetramethyl-, 1,4,6,9-tetramethyl-, and 1,3,7,9-tetra-methylthianthrene tetroxides gave the tetra-acids with 25% HNO3 at 220°C. These tetra-acids were converted to esters and anhydrides in the usual ways (69USP3410868). 

Fig. 4.52 Biocatalytic oxidation of alkyl groups on aromatic heterocycles.

Azonation of tertiary aliphatic amines has received some attention in recent years. Amine oxide formation was established long ago (1). Oxidation of alkyl groups was reported by Henbest and Stratford (2), Shulman (3), and Bailey et al. (4, 5). Formation of amine hydrochlorides was established when chlorinated solvents were used (2-5). De-alkylated products were formed (2, 4, 5), and amides were found by the same authors (2-5). 

The barbiturates can be metabolised by five major routes (1) hydroxylation of alkyl and aryl substituents at (e.g. pentobarbitone and phenobarb-itone) (2) A-dealkylation at the -position (e.g. methohexitone) (3) oxidation of alkyl groups at to give carboxylic acids (e.g. thiopentone) ... 

The oxidation of alkyl groups attached to the isoselenazole by heating with Se02 provides carboxylic acids subsequently converted into the methyl esters by treatment with diazomethane (Scheme 14) <1985H(23)127>. 

The oxidation of alkyl groups attached to the isoselenazole with Se02 provides the carboxylic acid derivatives (22) (Equation (5)). The dimethyl analogue provides a mixture of the mono-carboxylic isomers and the dicarboxylic compound. Other oxidants, such as potassium permanganate or chromic anhydride, fail <85H(23)127>. 

The introduction of a nonenolizable substituent on nitrogen allows the separation of 5-carboxylic acids and their derivatives. Such compounds have been prepared in a variety of ways, including the oxidation of alkyl groups (Eq. 15) or formyl groups (Eq. 16). Sheehan and Robinson carried out a similar reaction sequence (Eq. 17) using a diethylacetal. ... 

In Summary Benzyhc oxidations of alkyl groups take place in the presence of permanganate or chromate benzyhc alcohols are converted into the corresponding ketones by manganese dioxide. The benzyhc ether function can be cleaved by hydrogenolysis in a transformation that allows the phenylmethyl (benzyl) substituent to be used as a protecting group for the hydroxy function in alcohols. 

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