Propargyl alcohol selenium

Oxidation of the adducts formed from propargyl alcohols and selenium dihalides leads to formation of spiro selenuranes such as 102 and 103 (14S119). 

An innovative procedure for the synthesis of sulfur- or selenium-containing lactones from propargyl or homopropargyl alcohols involves the formal addition of ArS-Pd-X or ArSe-Pd-X to a multiple bond as the key stepJ" When a propargyl alcohol is treated with CO under Pd(0) catalysis in the presence of diarylsulfldes or diarylselenides, buteno-lides substituted in the /S-position with S- or Se-based residue are formed (Scheme 30). 

Electrochemically induced reactions have been a feature of selenium chemistry in the past two or three years. This year a potentially useful synthesis of ap-unsaturated aldehydes (279) has been reported and involves electrochemical generation of the active selenating species from diphenyl diselenide. Propargyl alcohols are thus selenated to give (279) in good to excellent yields. The ap-unsaturated aldehydes (279) are also formed when 1-lithioselenoalkenes, RCH=C(Li)SePh, react with DMF. Various other a-substituted alkenes are obtained in a similar fashion when DMF is replaced by other electrophiles. 

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