Sulfonate esters from alcohols

Carboxylic, and arylsulfonic acid halides react rapidly with pyridines generating 1-acyl- and 1-arylsulfonyl-pyridinium salts in solution, and in suitable cases some of these can even be isolated as crystalline, non-hygroscopic sohds. Solutions of these salts, generally in excess pyridine, are commonly used for the preparation of esters and sulfonates from alcohols, and of amides and sulfonamides from amines. 

An advantage that sulfonate esters have over alkyl halides is that their prepara tion from alcohols does not involve any of the bonds to carbon The alcohol oxygen becomes the oxygen that connects the alkyl group to the sulfonyl group Thus the configuration of a sulfonate ester is exactly the same as that of the alcohol from which It was prepared If we wish to study the stereochemistry of nucleophilic substitution m an optically active substrate for example we know that a tosylate ester will have the same configuration and the same optical purity as the alcohol from which it was prepared... 

An example of a sulfite ester made from thionyl chloride is the commercial iasecticide endosulfan [115-29-7]. A stepwise reaction of thionyl chloride with two different alcohols yields the commercial miticide, propaigite [2312-35-8] (189). Thionyl chloride also has appHcations as a co-reactant ia sulfonations and chlorosulfonations. A patent describes the use of thionyl chloride ia the preparation of a key iatermediate, bis(4-chlorophenyl) sulfone [80-07-9] which is used to make a commercial polysulfone engineering thermoplastic (see Polymers CONTAINING SULFUR, POLYSULFONe) (190). The sulfone group is derived from chlorosulfonic acid the thionyl chloride may be considered a co-reactant which removes water (see Sulfolanes and sulfones). 

Sulfonate esters are especially useful substrates in nucleophilic substitution reactions used in synthesis. They have a high level of reactivity, and, unlike alkyl halides, they can be prepared from alcohols by reactions that do not directly involve bonds to the carbon atom imdeigoing substitution. The latter aspect is particularly important in cases in which the stereochemical and structural integrity of the reactant must be maintained. Sulfonate esters are usually prepared by reaction of an alcohol with a sulfonyl halide in the presence of pyridine ... 

Compared with the fatty alcohol sulfates, which are also oleochemically produced anionic surfactants, the ester sulfonates have the advantage that their raw materials are on a low and therefore cost-effective level of fat refinement. The ester sulfonates are produced directly from the fatty acid esters by sulfona-tion, whereas the fatty alcohols, which are the source materials of the fatty alcohol sulfates, have to be formed by the catalytic high-pressure hydrogenation of fatty acids esters [9]. The fatty acid esters are obtained directly from the fats and oils by transesterification of the triglycerides with alcohols [10]. 

Most of the technically produced a-sulfo fatty esters are prepared from unbranched saturated fatty acid esters that are derived from 8 22 carboxylic acids and Cj-C3 alcohols. In particular the C12 (lauric), C14 (myristic), C16 (palmitic), and C18 (stearic) acids are interesting because the ester sulfonates... 

The surface and interfacial tension of a great number of ester sulfonates has been measured by Stirton et al. [26-28,30]. The values of the surface tension of 0.2% solutions at 25 °C are in the range from 25 to 50 mN/m and from 2 to 20 mN/m for the interfacial tension. In the group with the same number of C atoms the pelargonates and laurates have the lowest values. Among the esters of the same a-sulfo fatty acid, the surface and interfacial tension decreases with increasing molecular weight of the alcohols. Surface tension values also depend on the cation. For the alkali salts the values decrease from lithium to sodium to potassium. 

For a further separation of the sulfonated surfactants the latter are heated for 4 h with 2 N HC1. The methyl ester sulfonates are split into methanol and a-sulfo fatty acids, which form disodium salts after neutralization with NaOH. The product mixture from acid hydrolysis can be separated by extraction with petroleum ether. For example, the fatty alcohols formed from fatty alcohol sulfo-... 

Ester formation from polysaccharides can be achieved in several ways First by acylation of the OH groups with carboxylic or sulfonic acid azolides, second by converting the OH groups with imidazole carboxylates into carbonates, and third by reaction of an acid leash on the polysaccharide with an alcohol by means of CDI or analogous azolides. The acid leash might, for example, be a succinate attached to the polysaccharide. 

The group name is intended to cover esters derived from sulfenic, sulfinic and sulfonic acids, some of which are thermally unstable. This is especially so for esters of unsaturated alcohols, which are also liable to polymerise, catalysed by the liberated acids. Individually indexed compounds are ... 

With both building blocks 103 and 109 in hand, the total synthesis of lb was completed as shown in Scheme 17. Coupling of acid 103 and alcohol 109 under Yamaguchi conditions to give ester 110 and subsequent desilylation followed by chemoselective oxidation provided hydroxy acid 111. Lactonization of the 2-thiopyridyl ester derived from 111 in the presence of cupric bromide produced the macrodiolide 112 in 62% yield, which was finally converted to pamamycin-607 (lb) via one-pot azide reduction/double reductive AT-methylation. In summary, 36 steps were necessary to accomplish the synthesis of lb from alcohols 88 and 104, sulfone 91, ketone 93, and iodide rac-97. 

Section 7.8). Other classes of derivatives are thus most conveniently prepared from the sulfonyl chloride. Reaction with an alcohol leads to formation of a sulfonate ester. Two common sulfonyl chloride reagents employed to make sulfonate esters from alcohols arep-toluenesulfonyl chloride, known as tosyl chloride, and methanesulfonyl chloride, known as mesyl chloride (see Section 6.1.4). Note the nomenclature tosyl and mesyl for these groups, which may be abbreviated to Ts and Ms respectively. 

Mannitol hexanitrate is obtained by nitration of mannitol with mixed nitric and sulfuric acids. Similarly, nitration of sorbitol using mixed acid produces the hexanitrate when the reaction is conducted at 0—3°C and at —10 to —75°C, the main product is sorbitol pentanitrate (117). Xylitol, ribitol, and L-arabinitol are converted to the pentanitrates by fuming nitric acid and acetic anhydride (118). Phosphate esters of sugar alcohols are obtained by the action of phosphorus oxychloride (119) and by alcoholysis of organic phosphates (120). The 1,6-dibenzene sulfonate of D-mannitol is obtained by the action of benzene sulfonyl chloride in pyridine at 0°C (121). To obtain 1,6-dimethanesulfonyl-D-mannitol free from anhydrides and other by-products, after similar sulfonation with methane sulfonyl chloride and pyridine the remaining hydroxyl groups are acetylated with acetic anhydride and the insoluble acetyl derivative is separated, followed by deacetylation with hydrogen chloride in methanol (122). Alkyl sulfate esters of polyhydric alcohols result from the action of sulfur trioxide—trialkyl phosphates as in the reaction of sorbitol at 34—40°C with sulfur trioxide—triethyl phosphate to form sorbitol hexa(ethylsulfate) (123). 

Trialkylaluminums, 21 By geminal alkylation of carbonyl groups Dichlorodimethyltitanium, 216 From reduction of alkyl halides, alkyl sulfonates and similar compounds From acetates or other esters Triphenylsilane, 334 From alcohols... 

The preparation of alkyl halides by substitution reactions usually starts from alcohols because alcohols are widely available. Hydroxide ion is a poor leaving group, so the OH must first be converted into a better leaving group, either by protonation in acid or by conversion to a sulfonate or similar ester (see Section 8.9), as illustrated in the following equations ... 

Esters of aliphatic and aromatic sulfonic acids are conveniently prepared in high yields from alcohols and sulfonyl halides. A basic medium is required. By substituting sodium butoxide for sodium hydroxide in butanol, the yield of n-butyl p-toluenesulfonate is increased from 54% to 98%. Ethyl benzenesulfonate and nuclear-substituted derivatives carrying bromo, methoxyl, and nirro groups are prepared from the corresponding sulfonyl chlorides by treatment with sodium ethoxide in absolute ethanol the yields are 74-81%. Pyridine is by far the most popular basic medium for this reaction. Alcohols (C -Cjj) react at 0-10° in 80-90% yields, and various phenols can be converted to aryl sulfonates in this base. "... 

Coco-Based Surfactants. The most important coconut oil-based surfactants are fatty alcohol sulfate, fatty alcohol ether sulfate, and fatty alcohol polyglycol ether. Two relatively new coco-based surfactants are fatty acid methyl ester sulfonate and alkyl polyglycoside, which is produced from fatty alcohol and starch or sugar, both renewable materials. 

Fatty acid methyl esters sulfonate may be considered a material with a great potential. Its superior sequestering effect on water hardness gives it an advantage over fatty alcohol sulfate. The sulfonation of fatty acid methyl ester is different from that of fatty alcohol. The reaction mechanism involves two steps (31). In the first reaction, the SO3 gas reacts quickly to form sulfoanhydride. In the second step (which takes 40-90 min), the sulfoanhydride becomes the sulfonating agent, reacting with the still-unreacted ester. 

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