Reaction CV.—Action of Acid Anhydrides on Alcohols and Phenols

Reaction CV. Action of Acid Anhydrides on Alcohols and Phenols. 

Esterification is effected in the cold in presence of alkali or by heating the alcohol and anhydride together, usually in presence of a dehydrating agent—e.g., fused zinc chloride, anhydrous sodium acetate, etc. Preparation 204.—Mannitol Hexacetate. 

10 gins, of mannitol, 10 gms. of fused sodium acetate, and 40 gms. acetic anhydride are placed in a small flask provided with a reflux condenser and heated, at some distance above a wire gauze, to gentle boiling for an hour. The product is poured into water, well stirred and broken up with a glass rod. After some time it is filtered off, washed with water, and recrystallised from alcohol. 

CHaOH(CHOH)4CHaOH + 3(CH3C0)20 - C18H26Ola + 3Ha0. 

—Almost theoretical (24 gms.). Colourless crystals insoluble in water soluble in hot alcohol M.P. 119°. (B., 12, 2059.) 

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