Alcohols inorganic esters

The first successhil attempt to make textile fibers from plant cellulose can be traced to George Audemars (1). In 1855 he dissolved the nitrated form of cellulose in ether and alcohol and discovered that fibers were formed as the dope was drawn into the air. These soft strong nitrocellulose fibers could be woven into fabrics but had a serious drawback they were explosive, nitrated cellulose being the basis of gun-cotton (see Cellulose esters, inorganic esters). 

Commercial lecithin is insoluble but infinitely dispersible in water. Treatment with water dissolves small amounts of its decomposition products and adsorbed or coacervated substances, eg, carbohydrates and salts, especially in the presence of ethanol. However, a small percentage of water dissolves or disperses in melted lecithin to form an imbibition. Lecithin forms imbibitions or absorbates with other solvents, eg, alcohols, glycols, esters, ketones, ethers, solutions of almost any organic and inorganic substance, and acetone. It is remarkable that the classic precipitant for phosphoHpids, eg, acetone, dissolves in melted lecithin readily to form a thin, uniform imbibition. Imbibition often is used to bring a reactant in intimate contact with lecithin in the preparation of lecithin derivatives. 

Inorganic Esters. Boric acid and borax form cycHc esters with poly(vinyl alcohol) (85—100). The reaction is markedly sensitive to pH, boric acid concentration, and the cation-to-boron ratio. An insoluble gel is formed at pH above 4.5—5.0 ... 

The reaction of alkyl sulfates with alkoxide ions is quite similar to 10-12 in mechanism and scope. Other inorganic esters can also be used. One of the most common usages of the reaction is the formation of methyl ethers of alcohols and phenols by treatment of alkoxides or aroxides with methyl sulfate. The alcohol or phenol can be methylated directly, by treatment with dimethyl sulfate and alumina in cyclohexane. Carboxylic esters sometimes give ethers when treated with alkoxides (Bal2 mechanism, p. 473) in a very similar process (see also 10-24). 

The above transformations show a few of the many inorganic esters that can be prepared by attack of an inorganic acid or, better, its acid halide or anhydride, on an alcohol. Although for convenience all these similar reactions are grouped together, these are not all nucleophilic substitutions at R. The other possible pathway is nucleophilic substitution at the inorganic central atom ... 

When proton acids catalyze alcohol dehydration, the mechanism is El. ° The principal process involves conversion of ROH to ROHj and cleavage of the latter to R and H2O, though with some acids a secondary process probably involves conversion of the alcohol to an inorganic ester and ionization of this (illustrated for H2SO4) ... 

Alcohols form esters from inorganic acids as shown above. Like all esterifications, these reactions are reversible that is, in the presence of water and the right conditions, they revert to the original alcohol and acid. Nitrate esters are mainly used as explosives, but some have found use as diesel fuel additives. Note the difference between a nitrate ester such as ethyl nitrate (C2H5ONO2) and an organic nitro compound such as nitroethane (C2H5NO2). 

Linear Secondary Alcohol Ethoxylates (LSAE). The hydrophobes of LSAE are made via borate-modified oxidation of n-parafiins to form inorganic esters followed by hydrolysis. The resulting alcohols contain secondary hydroxyl groups randomly located along the linear alkyl chain. LSAE biodegrade slightly slower than LPAE (13.14). 

Problem 13.44 List the alcohols and acids that compose the inorganic esters (a) (CHj),COCl and (b) CHjCHjONO,. Name the esters. ... 

Alkyl sulfates, tosylates, and other esters of sulfuric and sulfonic acids can be converted to alkyl halides with any of the four halide ions.979 Neopentyl tosylate reacts with Cl, Br, or I without rearrangement in HMPA.980 Similarly, allylic tosylates can be converted to chlorides without allylic rearrangement by reaction with LiCl in the same solvent.981 Inorganic esters are intermediates in the conversion of alcohols to alkyl halides with SOCl2, PC15, PC13, etc. (0-67), but are seldom isolated. 

Reaction between alkoxides or arox-ides and alkyl halides (Williamson) 0-14 Reaction between alkoxides or arox-ides and inorganic esters 0-15 Alkylation of alcohols or phenols with diazo compounds 0-16 Dehydration of alcohols 0-17 Transetherification 0-19 Alkylation of alcohols with onium salts... 

This reaction is rapid and produces few side reaction products. In addition, the sulfur dioxide and hydrogen chloride formed as byproducts are gasses and therefore easily removed from the reaction. Mechanistically, the alcohol initially reacts to form an inorganic ester. 

In addition to forming esters with carboxylic acids, alcohols form inorganic esters with inorganic acids such as nitric acid, sulfuric acid, and phosphoric acid. In each type of ester, the alkoxy (—OR) group of the alcohol replaces a hydroxyl group of the acid, with loss of water. We have already studied tosylate esters, composed of para-toluenesulfonic acid and alcohols (but made using tosyl chloride, Section 11-5). Tosylate esters are analogous to sulfate esters (Section 11-13A), which are composed of sulfuric acid and alcohols. 

Cellulose is esterified with certain inorganic acids such as nitric acid, sulfuric acid, and phosphoric acid. A prerequisite is that the acids used can bring about a strong swelling thus penetrating throughout the cellulose structure. The esterification can be considered as a typical equilibrium reaction in which an alcohol and acid react to form ester and water. Of the inorganic esters cellulose nitrate is the only important commercial product. 

Table 11. Fluorination of Inorganic Esters of Aliphatic Alcohols with Tetrabutylammonium Fluorides...

Alcohols react with common inorganic oxyacids to produce inorganic esters. For instance, nitric acid reacts with alcohols to produce nitrates by substitution of nitrate, —ONO2, for hydroxyl, —OH. 

An ester is the product of the reaction of an alcohol with a carboxylic acid and is the organic version of an inorganic salt. What is an inorganic ester ... 

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