Oxidation, deprotection, and formylation reactions using tetra-n-butylammonium peroxydisulfate

Abstract

Tetra-n-butylammonium peroxydisulfate has turned out to be a useful source of tetra-n-butylammonium sulfate radical in organic solvents. Various 4,4``-dimethoxytrityl alkyl ethers reacted with tetra-n-butylammonium peroxydisulfate to produce the corresponding alcohols under mild and anhydrous conditions. This reaction may be proceed via radical process. This reaction can be used to deprotect 4,4``-dimethoxytrityl groups in nucleoside chemistry. p-Methoxybenzyl ethers were oxidized to the corresponding alkyl p-methoxybenzoate mainly in the presence of tetra-n-butylammonium peroxydisulfate under anhydrous conditions. But in hydrous conditions, the major products were alcohols and p-anisaldehyde, which were the deprotected products. The reaction may be explained by the lability of benzylic hydrogen. In the presence of water, the reaction intermediates were hemiacetal form, so these were cleaved to corresponding alcohols. In anhydrous conditions, hemiacetals could not be formed, so main products were esters. In the reactions of vinyl epoxides with tetra-n-butylammonium peroxydisulfate in 1,3-dioxolane solvent, δ-masked formylated products were produced.