Ethyl acetylate-based

Acetyl Ridnoleates n Plasticizers, such as butyl and ethyl acetyl ridnoleates. They can be regarded as esters of acetylated ricinoleic acid. The hydroxy group in the ricinoleic chain has been acetylated or esteri-fied, and the carboxylic group has also undergone esterification, but with an alcohol (Wypych G (ed) (2003) Plasticizer s data base. Noyes Publication, New York). 

The catalytic alcohol racemization with diruthenium catalyst 1 is based on the reversible transfer hydrogenation mechanism. Meanwhile, the problem of ketone formation in the DKR of secondary alcohols with 1 was identified due to the liberation of molecular hydrogen. Then, we envisioned a novel asymmetric reductive acetylation of ketones to circumvent the problem of ketone formation (Scheme 6). A key factor of this process was the selection of hydrogen donors compatible with the DKR conditions. 2,6-Dimethyl-4-heptanol, which cannot be acylated by lipases, was chosen as a proper hydrogen donor. Asymmetric reductive acetylation of ketones was also possible under 1 atm hydrogen in ethyl acetate, which acted as acyl donor and solvent. Ethanol formation from ethyl acetate did not cause critical problem, and various ketones were successfully transformed into the corresponding chiral acetates (Table 17). However, reaction time (96 h) was unsatisfactory. 

Ethyl 2,3,4-tri-O-acetyl-l-thio-a-L-rhamnopyranoside was synthesized by applying the reported method based on the BF3-Et20-catalyzed reaction of ethane... 

However, when considering the use of acid or base in organic solvents for sample extraction, care must be taken to avoid potential artifacts that may arise from side reactions. For example, methylation of active hydroxyl groups or acidic functions on the analyte may sometimes occur when acidic methanol is used as the extractant. Another example is acetylation of an active alcohol on the analyte following partition of the analyte into ethyl acetate from aqueous solution acidified with glacial acetic acid. 

Excellent ee-values (up to 94%) have been obtained for the hydrogenation of various 2-substituted N-acetyl indoles with an in-situ prepared rhodium catalyst modified with the trans-chelating diphosphine (S,S)-(R,R)-2,2"-bis[l-(diphenyl-phosphino)ethyl]-1,1"-biferrocene (Scheme 16.23) [88]. A strong base was required as co-reagent to observe both high conversion (TOFs of 50-100) and en-... 

The ethyl radical directly attacks the heteroaromatic base, while the acetaldehyde acts as a source of acetyl radical. Photochemical oxy-alkylation has also been tried with ethers. The reaction has been successfully carried out with pyridines, quinolines, isoquinolines,cinno-lines, and quinoxalines. Particularly good yields were obtained with caffeine (16) (Scheme 14). ... 

For the regeneration of ATP, we chose the system based in the use of acetyl phosphate as final phosphoryl donor because this affords several advantages (i) acetyl phosphate is easily obtained by acylation of phosphoric acid with acetic anhydride in ethyl acetate [24], and (ii) the resulting sodium acetate is a non-toxic and an environmentally compatible compound. However, this regeneration system is quite sensitive to pH changes. Thus, a continuous adjustment of the pH to 7.5 is needed to maintain the proper operation of the system. Perhaps the main aspect of this approach is that the DHAP must be formed at the same rate as it is consumed by the aldolase. To avoid the accumulation of DHAP and minimize its non-enzymatic degradation, fine tuning of the aldolase/DHAK activities is needed. This adjustment must be experimentally optimized for some acceptors. 

The preparatively useful and simple N-alkylation procedure that utilizes a combination of carboxylic acid and sodium borohydride has been applied to carbazole giving an efficient 9-ethylation. Also of preparative importance is the use of thallous ethoxide as base in dimethylformamide-ether 9-methyl-, 9-ethyl-, n-propyl-, n-butyl-, benzyl-, and n-allylcarbazoles were efficiently produced, as well as 9,9 -dicarbazolylalkanes using C3, C4, and Cg dihalides. 2-Acetyl- and 2-vinylcarbazole were also efficiently 9-ethylated by this route. Another more recent approach to N-alkylation of carbazole utilizes potassium terf-butoxide in the presence of a catalytic quantity of 18-crown-6 9-methylcarbazole was prepared in high yield. ... 

The condensation of 5-acetyl derivative 404 instead of the corresponding 5-formyl compound, with ethyl acetoace-tate, ethyl benzoylacetate, and diethyl acetone-1,3-dicarboxylate, by heating in the absence of base gave the respective 6-acylpyrido[2,3-4]pyrimidin-7(8//)-ones 406. The reaction of 404 with diethyl malonate afforded the 6-carboxylate 407 <2005RCB784>. Reaction of 405 with triethyl phosphonoacetate yielded 408 <2001W02001070741>. 

The second method of dissolution is based on solvolysis (Solvolysis method) (6,7,11,12). Under milder conditions (80°C for 30 to 150 min) phenolation was accomplished with an appropriate catalyst, and the chemically modified wood was dissolved in phenol (11). Under similar conditions, woods derivatized by allylation, methylation, ethylation, hydroxylation and acetylation have also been found to dissolve in polyhydric alcohols, such as... 

In an apparatus suitably protected against atmospheric moisture and fitted with a gas-inlet tube, mechanical stirrer, and an efficient reflux condenser, to a solution of 45 gm (0.45 mole) of ethyl isopropyl ketone and 5 gm of freshly distilled acetyl chloride is added, through the gas-inlet tube, 18 gm (0.24 mole) of ethyl nitrite at 45°-55°C over a 2 hr period. The reaction mixture is stored overnight in a refrigerator, whereupon 15.2 gm (48.7% based on ethyl nitrite used) of 2-methyl-2-nitroso-3-pentanone dimer (bimolecular ethyl a-nitroso-isopropyl ketone) deposits. The product is isolated by filtration, m.p. 122°-123°C. 

In the recent patent literature a procedure is given for coupling a diazonium salt with ethyl a-methylacetoacetate to afford an azo compound which could be used as an acetylating agent because its acetyl group was readily cleaved under mild conditions [26], In the coupling reaction, relatively weak bases such as pyridine, picolines, quinoline, and collidine are said to be effective. The example is given here for illustration only. It is to be noted that this is a composition of matter patent. 

Based on a suggestion by Odell and Earlam [119] that crown ethers and cryptands can cause proteins to dissolve in methanol, Broos and coworkers [120] investigated the effects of crown ethers on the enzymatic activity of a-chymotrypsin in the transesterification reaction of N-acetyl-L-phenylalanine ethyl ester with n-propanol in organic solvents. They observed a 30-fold rate acceleration when 18-crown-6 was used in octane. At that time, it was proposed that the water- and cation-complexing... 

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