Sucrose esters synthesis

A. L. Le Coent, M. Tayacout-Fayolle, F. Couenne, S. Bnamjon, J. Lieto, J. Fitremann-Gagnaire, Y. Queneau, and A. Bouchu, Kinetic parameter estimation and modelling of sucrose esters synthesis without solvent, Chem. Eng. Sci., 58 (2003) 367-376. 

As compared to the esterification of sucrose, cataly tic etherification of sucrose provides another family of non-ionic surfactants that are much more robust than sucrose esters in the presence of water. Synthesis of sucroethers can be achieved according to two processes (1) the ring opening of epoxide in the presence of a basic catalyst and (2) the telomerization of butadiene with sucrose using a palladium-phosphine catalyst. 

Okabe S, Suganuma M, Tada Y, Ochiai Y, Sueoka E, Kohya H, Shibata A, Takahashi M, Mizutani M, Matsuzaki T, Fujiki H (1999) Jpn J Cancer Res 90 669-676 Puterka GJ, Farone W, Palmer T, Barrington A (2003) J Econ Entomol 96 636-644 Wang Y (1988) Synthesis and application of sucrose ester. Light Industrial, London Kharchafi G, Jerome K, Adam 1, Pouilloux Y, Barrault J (2005) New J Chem 26 928-934 Van Rhijn W, De Vos D, Bossaert W, Bullen J, Wouters B, Grobet P, Jacobs P (1998) Stud SurfSci Catal 117 183-190... 

Sucrose reacts with diisocyanates leading to polyurethanes, which are used as thermal insulating foams, notably in cars. Partially protected sucrose esters can be used for the synthesis of better-defined polymers (Scheme 46).265 A first step of hydroxypropylation is sometimes necessary to obtain sufficient miscibility with the diisocyanate derivative, as well as for tuning the physicochemical properties of the polyurethane foams.78,305,420... 

J. Fitremann, A. Bouchu, and Y. Queneau, Synthesis and gelling properties of iV-palmitoyl-L-phenylalanine sucrose esters, Langmuir, 19 (2003) 9981-9983. 

Synthesis and Characterisation of Sucrose Esters. Partial sucrose esters were used as starting materials having the general formula Sue (OR) (OH) where n =... 

TABLE IV Synthesis by Diepoxide Route - Properties of Unpigmented Tetra Sucrose Ester Based Resin Films... 

Synthesis from sucrose ester/half-ester derivatives, monoepoxide and diisocyanate. Sucrose "penta"-soyate (the methanol insoluble fraction of the soap-free product) was reacted at 100°C for 4 hours with a mixture in xylene of 1 mole equivalent cyclic anhydride e.g., phthalic or tetrahydrophthalic anhydride and monoepoxide e.g., styrene oxide or Cardura E (the glycidyl ester of versatic acid), branched C9-Cfatty acids, in the presence of N-benzyl dimethylamine as catalyst. A faster rate was achieved with the phthalic system. The course of reaction between half ester carboxyl groups and epoxide groups was followed by acid value. About 90% reaction was achieved in all cases and to the product was added 1.0 mole toluene diisocyanate (the meucimum amount without gelation) and dibutyl tin dilaurate as catalyst. 

Synthesis from sucrose ester, aluminium diiso-propoxide monoacetylacetonate and diisocyanate. In pre-liminary experiments, sucrose "penta"soyate or sucrose "penta" dehydrated castor ester reacted in toluene at IIQOC with an equimolar proportion of aluminium diiso-propoxide monoacetylacetonate. (The latter was prepared separately by reaction of equimolar proportions of aluminium isopropoxide and acetylacetone in refluxing toluene with elimination of 1 mole 2-propanol). The modified sucrose ester reacted with 1.1 mole toluene diisocyanate (the maximum without gelation) and dibutyl tin dilaurate as catalyst. The performance of air-dried or stoved coatings was similar to material derived by the mono-/diisocyanate route in terms of alkali resistance, but they were more brittle. 

A systematic synthesis of sucrose esters began at the Research Ledaoratories of Tennessee Eastm m,in 1956. Simultaneously, evaluation of these preparations as potential commercial products with special emphasis as components of surface coatings was conducted by the Technical Service and Development Laboratories of Eastman Chemical Products. From this cooperative effort, success came in the form of a very unusual and unique compound, the mixed acetate-isobutyrate ester of sucrose - SAIB. 

The limited solubility of sucrose, the temperature sensitivity and tendency to carameliza-tion even below the melting point (185-186 °C) and the presence of three primary and five secondary hydroxyl groups, all of which can react, make the synthesis of sucrose esters a meticulous task. 

Monitoring the selectivity of sucrose esterifications is a real challenge. " For the purpose of preparing small analytical samples of sucrose esters with high selectivity at the primary positions, the sensitivity of 0-6 and 6 to steric hindrance can be exploited in Mitsunobu esterification conditions. Of course, this method is not acceptable for large-scale synthesis of commercial sucrose esters, but... 

The synthesis of sugar fatty acid esters has recently been described in several reviews [1-6]. In the following section, we highlight recent trends and provide a brief historical overview of the production of sugar fatty acid esters with particular emphasis on the sucrose esters. 

SCHEME 1 Ryoto sugar ester synthesis is based on transesteriiication of sucrose with a methyl fatty acid ester under conditions in which methanol is continuously removed. The product includes a complex mixture of K-soaps, diesters and mono-/ diglycerides, as well as the sucrose monoester when produced from crude beef tallow. An excess of sucrose is required (3 mol) to enhance the yield of the monoester over higher substituted products. DMF must be recovered for economic operation and because of its toxicity. 

Successful reduction of fat consumption requires both qualified fat substitutes and effective emulsifiers. Esters of sucrose and fatty acids can act either as non-caloric fats / 1 / or as surfactants / 2 / depending on the number of bound fatty acids. The objectives of this investigation were to synthesize a non- or low-caloric fat substitute as well as emulsifiers on the basis of sucrose esters of carboxylic acids in a solvent-free synthesis procedure suitable for human nutrition. 

Figure 41 Synthesis of sucrose esters by transesteriflcation of fatty acid methyl esters and sucrose. 

Scheme 4.2 Synthesis of sucrose esters by base-catalysed trans-esterification with fatty acid methyl esters (R COOMe), usually carried out in solvents (e.g. dimethyl formamide), microemulsions or solvent free.

A major drawback of the sucrose ester surfactants is the difficulty of synthesis due to the lack of mutual solubility between the sugar and the hydrophobic components, usually fatty acids. To obtain a commercially viable process, a good solvent for all components such as dimethylsulfoxide (DMSO) must be used. To make the final product meet FDA standards, the level of residual DMSO must be extremely low, requiring rigorous purification, implying high production costs. Nevertheless, the advantages of the family of products has led to a their commercial productions in limited quantities. 

Acidic Cation-Exchange Resins. Brmnsted acid catalytic activity is responsible for the successful use of acidic cation-exchange resins, which are also soHd acids. Cation-exchange catalysts are used in esterification, acetal synthesis, ester alcoholysis, acetal alcoholysis, alcohol dehydration, ester hydrolysis, and sucrose inversion. The soHd acid type permits simplified procedures when high boiling and viscous compounds are involved because the catalyst can be separated from the products by simple filtration. Unsaturated acids and alcohols that can polymerise in the presence of proton acids can thus be esterified directiy and without polymerisation. 

Aspartame (L-aspartyl-L-phenylalanine methyl ester [22839-47-0]) is about 200 times sweeter than sucrose. The Acceptable Daily Intake (ADI) has been estabUshed by JECFA as 40 mg/kg/day. Stmcture-taste relationship of peptides has been reviewed (223). Demand for L-phenylalanine and L-aspartic acid as the raw materials for the synthesis of aspartame has been increasing, d-Alanine is one component of a sweetener "Ahtame" (224). 

Enzymatic acylation reactions offer considerable promise in the synthesis of specific ester derivatives of sucrose. For example, reaction of sucrose with an activated alkyl ester in /V, /V- dim ethyl form am i de in the presence of subtilisin gave 1 -0-butyrylsucrose, which on further treatment with an activated fatty acid ester in acetone in the presence of Hpase C. viscosum produced the 1, 6-diester derivative (71,72). 

Sulfonate Esters. Sucrose sulfonates are valuable intermediates for the synthesis of epoxides and derivatives containing halogens, nitrogen, and sulfur. In addition, the sulfonation reaction has been used to determine the relative reactivity of the hydroxyl groups in sucrose. The general order of reactivity in sucrose toward the esterification reaction is OH-6 OH-6 > OH-1 > HO-2. 

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