Metal alkoxides reactions with hydrogen halides

Both reactants m the Williamson ether synthesis usually originate m alcohol pre cursors Sodium and potassium alkoxides are prepared by reaction of an alcohol with the appropriate metal and alkyl halides are most commonly made from alcohols by reaction with a hydrogen halide (Section 4 7) thionyl chloride (Section 4 13) or phosphorus tri bromide (Section 4 13) Alternatively alkyl p toluenesulfonates may be used m place of alkyl halides alkyl p toluenesulfonates are also prepared from alcohols as their imme diate precursors (Section 8 14)... 

Zirconium and hafnium tetraalkoxides are highly reactive compounds. They react with water, alcohols, silanols, hydrogen halides, acetyl halides, certain Lewis bases, aryl isocyanates and other metal alkoxides. With chelating hydroxylic compounds HL, such as j8-diketones, carboxylic acids and Schiff bases, they give complexes of the type ML (OR)4 these reactions are discussed in the sections dealing with the chelating ligand. 

In addition to the general procedure iUusIrated by Eq. (2.182), another route has been employed for the synthesis of metal alkoxides (and particularly analogous siloxides) by the reaction of metal alkoxides with esters (and silyl esters) (Section 4.3). Further, the reactions of metal alkoxides with acyl halides (or hydrogen halides) and unsaturated substrates such as CO, CO2, CS2, organic-isocyanates and isothiocyanates, chloral, etc. have been utilized for the preparation of haUde-alkoxides (Section 4.11) and interesting insertion products (Section 4.12), respectively. 

Chloride-modified transition metal alkoxides can be prepared by reaction of metal alkoxides with halides or hydrogen halides or by reaction of metal chlorides with alcohols [130] ... 

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