Formation of 3-acylamino-2-arylhydrazono-3-cyano-2,3-dihydro-1H-indoles in the reaction of 2-acylamino-3,3-dichloroacrylonitriles with arylhydrazines

The reaction of 2-acylamino-3,3-dichloroacrylonitriles with arylhydrazines in tetrahydrofuran upon heating was investigated. It led to previously unknown 3-acylamino-2-arylhydrazono-3-cyano-2,3-di-hydro-1H-indoles.     

Synthesis of difunctional derivatives in the furan and tetrahydrofuran series

Summary A number of previously unknown difunctional derivatives in the furan and tetrahydrofuran series was obtained by acetalization and liquid-phase hydrogenation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 389–391, February, 1965     

微波辐射条件下季戊四醇双缩醛和双缩酮化合物的合成

微波辐射硫酸锆-硅胶催化季戊四醇与醛、酮缩合反应,高收率制得了双缩醛和双缩酮化合物.该方法操作简便,收率高,催化剂可重复使用,是一种环境友好型催化反应.     

Synthesis of cyclic diacetals of fumaraldehyde, α, α'-dibromosuccinaldehyde,and but-2-ynedial

A number of cyclic diacetals of but-2-ynedial, fumaraldehyde, andα, α'-dibromosuccinaldehyde have been synthesized by the transacetalation of bis(dimethyl acetal)s of 1,2- and 1,3-glycols. The succinaldehyde derivatives have also been obtained by the bromination of the corresponding diacetals of fumaraldehyde.     

Synthesis and use of chiral substituted benzenes containing 1,2-diols protected as cyclic acetals

1,2-Dihydroxy benzenes have been protected as cyclic diacetals using 2,3-butane dione. These diacetals are extremely robust and can be further chemically diversified and resolved with chirality embedded in the 1,4-dioxane ring attached to the aromatic back bone as a result of the anomeric effect. These systems can serve as ligands, auxiliaries or organocatalysts for asymmetric synthesis.     

Synthesis of 2-alkoxy-3-chlorotetrahydrofurans

A simple one-stage method for the synthesis of 2-alkoxy-3-chlorotetrahydrofurans has been developed which is based on the chlorination of tetrahydrofuran with sulfuryl chloride at 55–65? C with the subsequent addition of an alcohol (without the isolation of the dichlorinated tetrahydrofurans). Eight compounds of the type mentioned have been synthesized by this method, six of them being previously unknown.     

Synthesis of 2-alkoxy-3-chlorotetrahydrofurans

A simple one-stage method for the synthesis of 2-alkoxy-3-chlorotetrahydrofurans has been developed which is based on the chlorination of tetrahydrofuran with sulfuryl chloride at 55–65 C with the subsequent addition of an alcohol (without the isolation of the dichlorinated tetrahydrofurans). Eight compounds of the type mentioned have been synthesized by this method, six of them being previously unknown.     

New Applications of Solid Silica Chloride (SiO 2 -Cl) in Organic Synthesis. Efficient Preparation of Diacetals of 2,2-Bis(Hydroxymethyl)-1,3-propanediol from Different Substrates and Their Transthioacetalization Reactions. Efficient Regeneration of Carbonyl Compounds from Acetals and Acylals

A new application of solid silica chloride, an easily available and efficient catalyst for the preparation of diacetal of 2,2-bis-(hydroxymethyl)-1,3-propanediol from aldehydes, acetals, acylals, and oximes, is described. Transthioacetalization of diacetals of 2,2-bis-(hydroxymethyl)-1,3-propanediol into their corresponding 1,3-dithianes and 1,3-dithiolanes in the presence of silica chloride is presented. Efficient regeneration of carbonyl compounds from their corresponding acetals, ketals, diacetals, and acylals in the presence of this catalyst also is described.     

Analysis of the component aldehyde and alcohols in borohydride-reduced dialdehydes from hexosamine derivatives

Unlike the dialdehydes formed from neutral monosaccharide residues, the dialdehydes from hexosamine residues are resistant to acidified ethanethiol, leaving the hemiacetal bond intact. However, the borohydride-reduced dialdehydes are readily split into the component aldehyde and alcohols; gas Chromatographic analysis of their derivatives is useful for structural studies of hexosamine-containing carbohydrates. Investigation by these sequential derivatization reactions indicated that anomeric methyl 2-acetamido-2-deoxy-$\text{d}$-glucopyranosides were oxidized in normal Malapradian fashion, whereas 2-acetamido-2-deoxy-$\text{d}$-glucose was over-oxidized. The rate of oxidation of 2-acetamido-D-glucitol was very rapid; the oxidation product can also be analyzed by the direct dithioacetal method (mercaptalation followed by trimethylsilylation).     

Formation of Heterocyclic and Polycyclic Compounds from Amino Alcohols and Dialdehydes

Amino alcohols typically react with aldehydes to produce oxazolidines. It was hypothesized that the condensation of several commercially available amino alcohols with dialdehydes would produce a series of bicyclic oxazolidines containing two secondary amines. However, there were remarkable differences in the type of products formed depending on the structure of the dicarbonyl compounds and the reaction conditions. When linear aliphatic dialdehydes such as glyoxal were used, the expected bis‐oxazolidines were not produced; instead, polycyclic structures or oxazines were formed. However, when cyclic dialdehydes such as 1,3/1,4 cyclohexane dicarboxaldehyde were used, they resulted in products bearing the desired oxazolidine moieties.     

Wittig reaction with arylidenemalonic dialdehydes

Conclusions Depending on the structure of the starting dialdehydes and the reaction conditions, substituted arylidenemalonic dialdehydes react with a carbalkoxymethylenetriphenylphosphorane at either one or both carbonyl groups.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 457–459, February, 1984.     

MICROWAVE-ASSISTED ACETALIZATION OF PENTAERYTHRITOL CATALYZED BY 12-TUNGSTOPHOSPHORIC ACID

Efficient conversion of carbonyl compounds and pentaerythritol to corresponding diacetals in the presence of 12-tungstophosphoric acid under microwave irradiation is described.     

Microwave assisted cyclocondensation of dialdehydes with chiral diamines forming calixsalen type macrocycles

Microwave irradiation of various dialdehydes and chiral diamines afforded chiral macrocyclic imines in moderate to good yields. Linked dialdehydes predominantly form [2+2] macrocycles whereas dialdehydes without linkers yield [3+3] macrocycles. This is the first report of template-free synthesis of calixsalen-type macrocycles formed in shorter reaction times under microwave conditions. In all the reactions, the salts of chiral diamines were used in contrast to the free diamines normally employed.     

Deoxygenation/dimerization of sugar derivatives with BF3·Et2O-Et3SiH: synthesis of a β-isonucleoside

Lewis acid-Et₃SiH induced deoxygenation of anomeric carbon of sugars generates tetrahydrofuran derivatives, accompanied by hitherto unknown dimeric products. If the reagent addition steps are reversed, tetrahydrofuran derivatives are obtained as the sole products, while only the dimeric products are isolated if Et₃SiH is excluded. One of the deoxygenated products has been transformed into a β-isonucleoside.     

Stereochemistry of bisdioxolane systems

A number of diastereomers of cyclic diacetals of succinaldehyde were obtained by transacetalation of succinaldehyde bis(dimethylacetal) with the optical antipodes of tosylglycerol. The configurations of the products were determined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1608–1610, December, 1973.     

Comparative reactivity of diacetals of the type (C2H5O)2CH(CH2)nCH(OC2H5)2

Summary The reactivity of diacetals in the reaction with vinyl ether in comparison with the diacetal of malonic dialdehyde increases in the following order: diacetal of glyoxal < malonic diacetal < succinic diacetal < glutaric diacetal < adipic diacetal.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1657–1658, September, 1965     

Chemistry of acetals

Summary Optimum conditions were developed for the preparation of 3-ethoxyacrolein, 3,3-diethoxypropionaldehyde, and 3,3-diethoxy~2-methylpropionaldehyde by the hydrolysis of the diacetals of malonaldehyde and methylmalonal dehyde in presence of p-toluenesulfonic acid and phosphoric acid.     

One‐Pot Synthesis and Characterization of Some New Types of 5,5′‐Disubstituted Bis(imidazolidine‐2,4‐diones)

The synthesis and structural elucidation of some novel 5,5′‐disubstituted spiro and nonspiro‐bis‐hydantoins are reported. The Bucherer Burge's method has been modified for the preparation of some 5,5′‐substituted bis(imidazolidine‐2,4‐dione) derivatives starting with diketones ( 1–5 ) and dialdehydes ( 6 , 7 ). In some cases, diastereoisomeric mixtures of compounds were obtained. The resulting bis‐hydantoins ( 8–11 , 13 , 14 ) have not to our knowledge been previously reported in the literature.     

Stereochemistry of didioxolanyl systems

Diastereomeric cyclic mono- and diacetals of p-phthalaldehyde, 2,5-diformylfuran, and 2,5-diformylthiophene were synthesized under conditions of thermodynamic and kinetic control. The ratios of the diastereomers and their configurations were determined by PMR spectroscopy.See [1] for communication I.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1330–1333, October, 1976.     

Syntheses and characterizations of oligo(azomethine ether)s derived from 2,2′-[1,4-enylenebis (methyleneoxy)]dibenzaldehyde and 2,2′-[1,2-phenylenebis (methyleneoxy)]dibenzaldehyde

The oligo(azomethine ether)s were synthesized via polycondensation of alkyl diamines with aromatic dialdehydes. Two series of dialdehydes,namely 2,2’-[l,2-phenylenebis(methyleneoxy)]dibenzaldehyde[2,2’-l,2-(PBMODB)]and 2,2’- [l,4-phenylenebis(methyleneoxy)]dibenzaldehyde[2,2’-l,4-(PBMODB)]were prepared from the condensation reactions of salicylaldehyde with o-xylenedibromide and /7-xylenedibromide,respectively.The structures of dialdehydes and oligomers were determined by FT-IR,’ H-NMR and 13C-NMR.The thermal analyses of oligomers were conducted by DSC and TG/DTA techniques,respectively.Size exclusion chromatography(SEC) technique was also used to determine molecular weights and molecular weight distributions of oligomers.Electrochemical properties of the synthesized products were investigated.