Detellurative methoxylation

The detellurative methoxylation of the telluroxides also proceeds in high yields by treatment with trifluoroperoxyacetic acid (generated in situ from TFA and (method C). 

Detellurative methoxylation of alkyl phenyl tellurides (typical procedure)2-Methoxy 3-phenyltelluro-l,2,3,4-tetrahydronaphthalene (1.85 g, 5 mmol) is treated with MCPBA (3.3 g, 15 mmol) in MeOH (30 mL) at 25°C with stirring. After 1 h the mixture is treated with aqueous Na2S203 followed by aqueous NaHCOj and extracted with ether (3x30 mL). The extract is dried (MgS04) and evaporated, to leave a residue which is purified by Si02 TLC (eluting with hexane/EtOAc, 4 1) to afford pure tranx-2,3-dimethoxy-l,2,3,4-tetrahy-dronaphthalene (0.37 g, 1.94 mmol) and the c/x-isomer (0.15 g, 1.76 mmol (54%)). 

The title compounds, important anti-inflammatory pharmaceuticals, can be synthesized starting from aromatic ketones, as depicted in the accompanying scheme, involving the above-described detellurative methoxylation in the key step. - ... 

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