Acetic anhydride with sucrose

Acetylsucrose [63648-81-7] has been prepared in 40% yield by direct acetylation of sucrose using acetic anhydride in pyridine at 40° C (36). The 6-ester has subsequently been obtained in greater than 90% yield, by way of 4,6-cycHc orthoacetate. Other selective methods for the 6-acylated derivatives include the use of alkyl tin reagents such as dibutyl tin oxide (37) and of dibutyl stannolane derivatives (38). Selective acetylation of sucrose by an enzymic process has also been described. Treatment of sucrose with isopropenyl acetate in pyridine in the presence of Lipase P Amano gave, after chromatography, 6-0-acetylsucrose (33%) and 4/6-di-O-acetylsucrose (8%). The latter compound has been obtained in 47% yield by the prolonged treatment (39). 

The structure of the levan synthesized by the action of B. subtilis on sucrose was determined by Hibbert and Brauns.89 Levan, in a yield of 60-65% calculated on the D-fructose part of the sucrose, was obtained by precipitation of the concentrated culture into methanol, and purified by reprecipitation and electrodialysis. Hydrolysis of purified levan with 0.5% aqueous oxalic acid for one hour at 100° gave a 99% yield of crystalline D-fructose. Triacetyllevan was prepared by treatment with acetic anhydride in pyridine, and deacetylation with alcoholic alkali yielded material identical with the original levan.940... 

A solution of sucrose (2.5 g) in dry pyridine (50 mL) was treated with benzylidene bromide (2.8 mL) at 85°C for 1.5 h. After a further addition of benzylidene bromide (1 mL), the reaction mixture was heated at 95°C for 0.5 h, treated with acetic anhydride (5 mL) at 0°C, and then stored at room temperature for 5 h. The solution was poured into ice water and extracted with dichloromethane, and the organic layer was washed with water and dried (NajSOj). The TLC (4 1 ether/light petroleum) showed a mixture of four products. The / f of the slow-moving spot was identical with that of sucrose octa-acetate, and the second, fast-moving spot was the major product The solution was concentrated and fractionated on a column of silica gel (200 g), using 1 1 ether/light petroleum. 1 2,3,3, 4, 6 -Hexa-0-acetyl-4,6-0-benzylidene-sucrose 33 (1.7 g, 35%), which crystallized in the tubes of the fraction collector, had an m.p. of 155-157°C, [a]D +44.3° (c 0.82, chloroform). 

According to both the NFPA Guide and Bretherick (Refs 5 13), sulfuric acid causes explosions and/or fires when in intimate contact with a large number (over 70) of materials including acetic anhydride, acet and nitric acid, acrolein, alcohols, alcohols and hydrogen peroxide, anun hydroxide, aniline, bromine and metals, carbides, chlorates, cyclopentadiene, ethylene glycol, various hydrocarbons, hydrochloric acid, iron, mercuric nitride, powdered metals, perchlorates, picrates, pyridine, Na carbonate, steel, sucrose, vinyl acetate, and w. Illustrative... 

Sucrose Acetate Isobutyrate occurs as a clear, pale yellow, viscous liquid. It consists of a mixture of sucrose esters of acetic and isobutyric acid, with sucrose diacetate hexaisobu-tyrate being the predominant sucrose ester. It is produced through the controlled esterification of sucrose with acetic anhydride and isobutyric anhydride. It is very soluble in essential oils such as orange oil, soluble in ethanol and in ethyl acetate, and very slightly soluble in water. 

Incidental reactions that have been reported include the preparation of derivatives of 5-(hydroxymethyl)-2-furaldehyde by reaction of D-fructose in acetic or propionic acid in the presence of the respective anhydride.158 The condensation of D-glucose with phenol has been effected in acetic acid in the presence of dry hydrogen chloride, prior to resinification,157 and the reaction of sucrose with thionyl chloride in acetic acid-acetic anhydride produced partially acetylated chlorodeoxysucroses.158 Sucrose has been condensed with maleic anhydride in acetic anhydride mixed with acetic acid or formic acid, to give solid products having an undetermined structure.159... 

Sucrose (25 mg) in dry pyridine (500 gl) is treated with benzylidene bromide (28 fi ) at 85 °C for an hour then a further 10 /rl of benzylidene bromide is added and the reaction mixture is heated at 95 °C for a further 30 min. The product is acetylated with 50 /il of acetic anhydride at room temperature for 5 h. The solution is poured into ice-water and extracted with dichloro-methane. After water washing, the lower layer is dried over anhydrous sodium sulphate it may be used for analysis by TLC or further purified on a silica gel column [23]. 

The compositions of the product mixtures from the treatment of sucrose with acetic anhydride are given in Tables IV and V. it is seen that, with 1,3 moles of acetic anhydride, the cobalt chelate formed from sucrose, sodium hydride and cobaltous chloride, in the mole ratio 2 4 1, gives 98 mole-% of monoacetates. 

Table IV Composition of the acetylation products of sucrose chelates and alcoholates with acetic anhydride in DMF, 15h, 22°C, mole-%.

Figure 1. Extent of acetic anhydride inhibition of electron transport activity as a function of pH.- Chloroplasts were treated with acetic anhydride in reaction media containing 0.1 M sucrose, 50 mM KCl,...

Derivation By controlled esterification of sucrose with acetic and isobutyric anhydrides. 

Sucrose acetate isobutyrate (SAIB, Scheme 9.3.7) is a mixed sucrose polyester prepared by reaction of sucrose with acetic and isobutyric anhydrides. It is by far the largest industrially utilized sucrose ester and covers food (weighting agent in beverages) as well as non-food applications (gloss and adhesion improvement in lipstick and nail polish, pigment dispersion). ... 

Acylation of sucrose generally is performed with the appropriate acid anhydride or acyl halide in pyridine at or below room temperature. The most common acyl derivatives of sucrose used are acetates and ben-... 

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