Synthesis of substituted quinones via organotellurium compounds

Carbon-centred radicals, generated under photo-thermal conditions from organotellurium compounds, react with a variety of quinones to afford the mono addition products in good yields.  

The reaction in the dark is slow, but eventually gives the same product by heating at 100°C. The effect of the solvent is marginal. 

Reaction of organotellurium compounds with quinones (typical procedure, 2-benzyl-l, 4-benzoquinone) A solution of benzyl p-methylphenyl telluride (111 mg, 0.36 mmol) and 1,4-benzoquinone (78.0 mg, 0.72 mmol) in benzene (0.6 mL) in a Pyrex tube was irradiated with a 200 W high-pressure mercury lamp at 100°C for 1 h. After the solvent was removed under reduced pressure, the crude mixture was purified by flash chromatography (silica gel 6.4 g elution with 5% ethyl acetate in hexane) to give the product in 57% yield. 

The reaction has been applied for the synthesis of polyprenyl quinol natural product ubiquinone and vitamin K. 

The photolytic reaction of acyltellurides with quinones surprisingly takes place at the oxygen moiety. 

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