Magnesium/alcohols ethylmagnesium bromide

Other hydrides used for the conversion of esters to alcohols are magnesium aluminum hydride in tetrahydrofuran [89, 577] and magnesium bromohydride prepared by decomposition of ethylmagnesium bromide at 235° for 2.5 hours at 0.5mm [7055]. They do not offer special advantages (the latter giving only 35% yield of benzyl alcohols from ethyl benzoate). 

For example, ethylmagnesium bromide reacts with oxirane (ethylene oxide) to form the magnesium salt of butan-l-ol. Protonation gives the neutral alcohol. 

Lactone synthesis. This Ti(II) complex can serve as catalyst for hydro-magnesiation of allylic or homoallylic alcohols, prepared by addition of vinyl- or allyl-Grignard reagents to ketones. Ethylmagnesium bromide is used as the source of magnesium hydride. The carbonylation of the organomagnesium intermediate results in a -y- or a 5-lactone (equation I). 

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