Alkylation, -hydroxyketones Alcohols

Although significant improvements have been made in the synthesis of phenol from benzene, the practical utility of direct radical hydroxylation of substituted arenes remains very low. A mixture of ortho-, meta- and para-substituted phenols is typically formed. Alkyl substituents are subject to radical H-atom abstraction, giving benzyl alcohol, benzaldehyde, and benzoic acid in addition to the mixture of cresols. Hydroxylation of phenylacetic acid leads to decarboxylation and gives benzyl alcohol along with phenolic products [2], A mixture of naphthols is produced in radical oxidations of naphthalene, in addition to diols and hydroxyketones [19]. 

Preparation of ethers. Treatment of secondary and tertiary alcohols with dimsylsodium in DMSO followed by alkylation with a dialkyl sulfate gives ethers in 60-90% yield. The presence of ester and tertiary amino groups and of double bonds docs not interfere with the reaction. However, alkylation of a- or j8-hydroxyketones was not successful by this procedure. 

A catalyzed alcohol reaction (b) on lignin takes place at -hydroxyketones, carbonyl, and carboxyl groups. The reactions give different products and are shown in equation 3. Since alcohol/acid alkylation does not alkylate the aromatic hydroxyl groups (108), alkyllignins fiom these reactions have sharply different solubility... 

---