Etherification, and hydrolysis

Ultrasound Esterifications, etherification and hydrolysis of esters Michael addition involving the addition of chalcone to diethyl malonate in SLPTC mode Synthesis of benzyl sulfide by reaction of solid sodium sulfide with benzyl chloride Synthesis of fiuvenese from phenylacetylene Davidson et al. (1987) Raioarinoro et al. (1992) Contamine el al. (1994) Hagenson et al. (1994) Wang and Zhao (1996)... 

The synthesis of acrylate materials is relatively straight forward, and can be performed without the recourse to complex reagents and equipment, but, because of the polymerization step may require particular care to ensure the purity of the final material. This is particularly so in the following example, where a cyanobenzoate ester is used to provide the anisotropic phase structure, since the electron-withdrawing group makes this ester particularly susceptible to hydrolysis. The first step in the production of a mesogenic monomer involves the acetylation of 6-chlorohexanol using a standard preparative procedure,followed by etherification and subsequent hydrolysis as shown in Scheme 1. 

Examples. Either or both microwave reactors have been useful for processes such as esterification, amidation, transesterification, rearrangement, acetalization, nucleophilic substitution, hydrolysis of esters and amides, isomerization, decarboxylation, oxidation, elimination, etherification, and formation of aminoreductones. Examples of such reactions have been tabulated (2,3). 

Only a very few reactions, detailing straightforward functional group transformations, such as etherification and nitrile hydrolysis, have been reported for derivatives of the completely unsaturated pyrrolo[I,2-o]-pyrimidine nucleus (Scheme 3). In addition, hydrolysis of a substituted 8-cyanopyrrolo[ l,2-a]pyrimidine (25) to 4-aryl-2-aroyl-8-carboxamido-6,7-dimethylpyrrolo[1.2-a]pyrimidine (85) has been reported.10... 

Catalyst-resin beads placed in cloth bags attached to fiberglass strip. Strip wound around helical stainless steel mesh spacer Ion exchange resin beads used as column packing Etherifications Cumene Hydrolysis of methyl acetate Smith et ah, U.S. Patent 4,443,559 (1981) Shoemaker and Jones, Hyd. 57(6), 57 (1987) Fuchigami,/. Chem. Eng. Jap., 23, 354(1990) Crossland, U.S. Patent 5,043,506 (1991) Flato and Hoffman, Chem. Eng. Tech., 15, 193(1992) Zhang et ah, Chinese Patent 1,065,412 (1992) Sanfilippo et ah, Eur. Pat. Apph EP 470,625 (1992) Wang et ah, Chinese Patent 1,060,228 (1992)... 

The 1,5-anti-aldol reaction was performed with chiral boron enolate of 325 and aldehyde 327, prepared by Evans asymmetric alkylation, cross metathesis, and Wittig homologation (Scheme 72), to afford 324 with a 96 4 diastereoselectivity. Stereoselective reduction of C9-ketone provided the 5y -l,3-diol, which was exposed to catalytic f-BuOK to give 2,6-cis-tetrahyderopyran 333 via an intramolecular Michael reaction. Finally, methyl etherification, deprotection, hydrolysis of ester, and Yamaguchi macrolac-tonization yielded the leucascandrolide macrolide 201 (Scheme 73). 

Alkyl nitrites in a liquid phase readily undergo hydrolysis, etherification, and other equilibrium reactions in terms of the following scheme yielding alcohols, alkyl nitrate, esters of organic acids, ethers and olefins [4] ... 

Symmetrical hexacatenars such as the first described phasmids were obtained as follows (Scheme 1) The three-chain derivative 2 was obtained by etherification of ester 1 with three equivalents of the required n-alkyl bromide, followed by saponification and hydrolysis (a). Esterification of acid 2 chloride with p-nitrophenol (b) afforded ni-troester 3, which was reduced to the corresponding aminoesterd (c). Finally, phasmid 5 was obtained by reaction of two equivalents of 4 with terephthaldehyde. 

Reaction of olefin oxides (epoxides) to produce poly(oxyalkylene) ether derivatives is the etherification of polyols of greatest commercial importance. Epoxides used include ethylene oxide, propylene oxide, and epichl orohydrin. The products of oxyalkylation have the same number of hydroxyl groups per mole as the starting polyol. Examples include the poly(oxypropylene) ethers of sorbitol (130) and lactitol (131), usually formed in the presence of an alkaline catalyst such as potassium hydroxide. Reaction of epichl orohydrin and isosorbide leads to the bisglycidyl ether (132). A polysubstituted carboxyethyl ether of mannitol has been obtained by the interaction of mannitol with acrylonitrile followed by hydrolysis of the intermediate cyanoethyl ether (133). 

Countercurrent flow has advantages in product and thermodynamically limited reactions. Catalytic packings (see Figure 9. Id) are commonly used in that mode of operation in catalytic distillation. Esterification (methyl acetate, ethyl acetate, and butyl acetate), acetalization, etherification (MTBE), and ester hydrolysis (methyl acetate) were implemented on an industrial scale. 

Most of the selective-etherification studies on polysaccharides have been made with cellulose, and nearly all of them have involved quantitative separation of the D-glucose derivatives formed on hydrolysis of the partially substituted celluloses. In view of their stability, ethers of polysaccharides are particularly suited to this approach. 

Blocking the C-l OH of D-fructose and L-sorbose (Scheme 25) was effected in excellent yields through regioselective isopropylidene acetalation of the free ketoses, followed by etherification (benzylation or allylation) of the remaining primary alcohol. Acid-catalyzed hydrolysis of the isopropylidene groups and condensation with HSCN efficiently produced a sole fused bicyclic OZT. 

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