Di O-Alkyl Derivatives of 1,2-Dihydroxy Compounds

Because of their interest as natural products 1,2-dimethylether derivatives from 

In the area of oxidative dimerisation, a solution of 3,4-dimethoxytoluene in dichloromethane was added to silica gel impregnated with ferric chloride. After the solvent had been removed and the residue left for 1 hour, 2,2 -dimethyl-4,4, 5,5 -tetramethoxybiphenyl was formed in 95% yield (ref.74). 

Oxidative dimerisation at the side-chain has been described as relevant to the synthesis of lignans (ref.75). Methyl 3,4-dimethoxybenzoylacetate in refluxing aqueous acetonitrile treated with potassium persulphate and a small amount of copper sulphate in an inert atmosphere produced after several hours (monitored by TLC), the dimer shown (racemateimeso 3 1) in 58% yield. 

2-Dialkoxybenzenes and benzenecrown ethers when submitted to mixed anodic trimerisation afford triphenylenes which possess one or two complexing sites (ref.76). Intramolecular oxidative reactions familiar in the area of morphine 

Another spiro compound has been obtained from the oxazolidine illustrated by the use of essentially the same reagent (ref.78). N-3-trichloroethoxycarbonyl-(2R)-4-hydroxybenzyl-(5S)-3,4-dimethoxyphenyloxazolidineindichloromethane upon treatment with vanadium oxyfluoride in trifluoroacetic/trifluoroacetic anhydride at -78 to-10 C afforded the para-para coupling product. 

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