Alkenes to a-Methoxyalkenes

The addition of phenyl tellurium tribromide to internal alkenes in methanol as solvent gives v/c-methoxyalkyl phenyl tellurium dibromides. Treatment of these dibromides with 0.5 M aqueous sodium hydroxide solution produces (x-methoxyalkenes via an intermediate alkyl phenyl tellurium oxide The same reaction sequence but starting with terminal olefins or cyclohexene leads to 2-methoxy-l-alkyl phenyl tellurium oxides, which decompose only at 250° in a vacuum. 

An analogous reaction of (Z)-4-octene produced the fAreo-tellurium di bromide, which formed 5-methoxy-3-octene. The stereochemistry of this compound was not determined.  

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