Silver monoacetate

CAS 563-63-3 EINECS/ELINCS 209-254-9 Synonyms Acetic acid silver salt Acetic acid, silver (1+) salt Silver (I) acetate Silver (1+) acetate Silver monoacetate... 

Silver matt powder. See Tin Silver monoacetate. See Silver acetate Silver monofluoride. See Silver fluoride Silver nitrate... 

Alternate Names silver acetate silver monoacetate. 

The reaction is carried out over a supported metallic silver catalyst at 250—300°C and 1—2 MPa (10—20 bar). A few parts per million (ppm) of 1,2-dichloroethane are added to the ethylene to inhibit further oxidation to carbon dioxide and water. This results ia chlorine generation, which deactivates the surface of the catalyst. Chem Systems of the United States has developed a process that produces ethylene glycol monoacetate as an iatermediate, which on thermal decomposition yields ethylene oxide [75-21-8]. 

Alkaline hydrolysis of 12-acetylnapelline (38) yielded an amino alcohol identical to napelline (34). This result indicated that the new alkaloid was napelline monoacetate. Treatment of 12-acetylnapelline with acetic anhydride and pyridine gave the triacetate 39. The latter was selectively hydrolyzed by alkali to afford 1-acetylnapelline (40). Oxidation of 38 with silver oxide yielded dehydro derivative 41, a result that revealed the presence of an a-hydroxy group at C-l in 38. Hydrogenation of 12-acetylnapelline over a... 

As mentioned above, the triacyl-/3-D-ribopyranosyl halides may react with alcohols in the presence of an acid acceptor to give orthoester derivatives. Thus Levene and Tipson56 showed that triacetyl-/3-D-ribopyranosyl bromide reacts with methanol in the presence of silver carbonate to give 3,4-diacetyl-D-ribopyranose methyl 1,2-orthoacetate (LXIV) while Klingensmith and Evans135 obtained an analogous compound (LXV) upon condensing dihydroxyacetone monoacetate with the same halide. The structures of these two orthoesters, LXIV and LXV, have recently been discussed by Pacsu.186... 

The Leukart reaction has also been used in the conversion of dehydroepiandro-sterone into 17/3-formylamino-3/3-formyloxyandrost-5-ene, which on reduction with lithium aluminium hydride afforded 3/3-hydroxy-17/3-me thylaminoandrost-5-ene. Acylation with isocaproyl chloride then furnished the N-methyl-N-isocaproyl steroid (197), after selective ester hydrolysis of the initially formed ON-diacyl derivative. The amide (197) was further converted into its 3,5-cyclo-6-ketone via the 3,5-cyclo-6/3-alcohol and thence by reaction with hydrogen bromide into the corresponding 3/3-bromo-5a-6-ketone which upon dehydrobromination furnished a A2-5a-6-ketone and ultimately the 2-monoacetate of the 2/3,3/3-diol (198) after reaction with silver acetate and iodine. Hydrolysis to the 2/3,3/3-diol (198) gave a separable mixture of the 2/3,3/8-dihydroxy-5a- and -5/3-ketones.88... 

Thallium monoacetate, TIOCOCH3 (hygroscopic), behaves similarly to silver acetate or silver benzoate. In the presence of iodine, it accomplishes stereoselective hydroxylations of alkenes [410]. 

S1097>. Reactions of phenanthrene-9,10-imine (20 R = H) with nucleophiles like NaN3 or RSCN under phase-transfer conditions gives compounds (62) and (63) respectively <84JHC1597>, while (20 R = C1) undergoes an unusual transformation to 9,10-phenanthroquinone dialkyl monoacetal (64) in a silver-promoted reaction (Scheme 23) <84JHC1593>. 

Conrow and Bernstein63 recommended the use of cadmium carbonate instead of silver salts to prepare glucosiduronic acids of phenolic steroids. The yields are usually better than those obtained by use of silver salts. Rohle and Breuer64 also used cadmium carbonate in the synthesis of a glucosiduronic acid of estra-l,3,5(10)-trien-2,3,17/3-triol 17-monoacetate, which is oxidizable with silver salts. Thus, methyl tri-O-acetyl-a-D-glucopyranosyluronate bromide (27), on reaction with estrone (28) afforded 3-0-(methyl 2,3,4-tri-O-acety 1 -/3-D-glucopy-ranosyluronate)estrone (29). 

They also reported the synthesis of acanthacerebroside A33 134, which was isolated from the starfish Acanthaster planci.34 DCC-mediated condensation of 129 and (R)-2-acetoxytetradocosanoic acid 130 afforded the ceramide monoacetate 131. The glycosidation of 131 with 2,3,4,6-tetra-O acetyl-p-D-glucopyranosyl bromide 132 in the presence of silver triflate and molecular sieves gave a mixture of the p-monoglycoside 133 and a diglycoside in 37 and 15% yield, respectively. Hydrolysis of 133 yielded acanthacerebroside A 134. 

The formation of 1,2-diol products from alkenes can be achieved using Prevost s reagent - a solution of iodine in carbon tetrachloride together with an equivalent of silver(l) acetate or silver(I) benzoate. " Under anhydrous conditions, this oxidant yields directly the diacyl derivative of the anh-diol (Prdvost conditions), while in the presence of water the monoester of the syn-diol is obtained (Woodward conditions). Thus, treatment of a cw-alkene with iodine and silver benzoate in boiling carbon tetrachloride under anhydrous conditions gives the tra 5-dibenzoate (5.92). With iodine and silver(I) acetate in moist acetic acid, however, the monoacetate of the cw-1,2-dihydroxy compound is formed. 

Retinol-11,12- H2 of low specific activity has been prepared (Isler et al., 1960) based on the work of Isler et al. (1947) on the synthesis of retinyl acetate. The same sequence of reactions as shown in Fig. 8, with several improvements in technique because of the small scale, was applied by Perry et al. (1982) to the preparation of retinoic acid tritiated at very high specific activity. Pure, recrystallized diol (XXVI) was partially hydrogenated with tritium over Lindlar catalyst in the presence of quinoline and the dihydro compound (XXVII), acety-lated in such a way as to afford mainly the monoacetate (XXVIII). Exposure of the acetate at low temperature for a very short time to very dilute hydrogen bromide in methylene chloride gave, after chromatography, pure retinyl-11,12- H2 acetate (XXIXa). Simultaneous hydrolysis and oxidation of the retinyl acetate by silver oxide in aqueous methanolic sodium hydroxide then yielded all-fran -reti-noic-11,12- H2 acid (Vllh). The specific activities obtained ranged from 25 to 40 Ci/mmol. 

Displacement. When meso-s i b n dibromide is heated with silver acetate under anhydrous conditions, the product is the meso-diol diacetate (eq 5). However, when the starting material is heated for 10 min on a steam bath with silver acetate, acetic acid, and water, a significant amount of ( )-diol monoacetate is formed.4... 

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