Regio- and stereoselective reactions of a rhodanine derivative with optically active 2-methyl- and 2-phenyloxirane

The reaction of a rhodanine derivative (=(Z)-5-benzylidene-3-phenyl-2-thioxo-1,3-thiazolidin-4-one; 1) with (S)-2-methyloxirane (2) in the presence of SiO₂ in dry CH₂Cl₂ for 10 days led to two diastereoisomeric spirocyclic 1,3-oxathiolanes 3 and 4 with the Me group at C(2) (Scheme 2). The analogous reaction of 1 with (R)-2-phenyloxirane (5) afforded also two diastereoisomeric spirocyclic 1,3-oxathiolanes 6 and 7 bearing the Ph group at C(3) (Scheme 3). The structures of 3, 4, 6, and 7 were confirmed by X-ray crystallography (Figs. 1 and 2). These results show that oxiranes react selectively with the thiocarbonyl group (CS) in 1. Furthermore, the nucleophilic attack of the thiocarbonyl S-atom at the SiO₂-activated oxirane ring proceeds with high regio- and stereoselectivity via an S_N2-type mechanism.     

Reactions of carbethoxycarbene with enaminones. Formation of unexpected pyrroles

The reactions of carbethoxycarbene (:CH₂-CO₂Et, 2) with several acyclic enaminones (RCOCH=CR¹NHR², 3) lead to the unexpected formation of 2-Me, 3-CO₂Et, 4-H, 5-R¹-pyrroles 4 . Structural variations of the enaminones show that the structural fragments C(3)-CO₂Et and C(2)-Me are provided by 2 and that the fragment C(5)-R¹NHR² originates from the enaminones 3 , while the RCO group from 3 is eliminated during the course of reaction. Reactions with cyclic and nitrogen-hindered enaminones do not lead to pyrrole formation but occur by simple insertion of 2 to the Cα-H bond.     

2-Lithiated-2-phenyloxetane: a new attractive synthon for the preparation of oxetane derivatives

A valuable and direct method to access 2-substituted-2-phenyloxetanes by electrophilic quenching of the corresponding 2-lithiated derivative has, for the first time, been described. 2-Lithiated-2-phenyloxetane was found to be configurationally unstable. Evidence is presented to show that electron-transfer processes are also operative in the coupling reactions with electrophiles.     

Reaction of 2-acetylbenzothiazole with 2-formylbenzothiazole

Products of condensation of 2-acetylbenzothiazole with 2-formylbenzothiazole and other aldehydes of the heterocyclic series were obtained, and their structures and properties were investigated. It is shown that some of them react with acids or alkalis to give dyes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 644–648, May, 1982.     

Reaction of 2-Alkoxypropenals with 2-Mercaptoethanol

The reaction between 2-alkoxypropenals and 2-mercaptoethanol was studied at 20 and 60°C by means of ^1HNMR and GC-MS methods. Under kinetically controlled conditions (20°C, 7-30 days) with no catalyst the addition of 2-mercaptoethanol to 2-alkoxypropenals occurs along Markownikoff rule. The arising 2'-hydroxyethylthio-2-alkoxypropanal undergoes isomerization into the 2-hydroxy-3-alkoxy-3-methyl-1,4-oxathiane that at heating in the presence of catalytic amounts of acids is converted into 2-methyl-2-formyl-1,3-oxathiolane. The reaction of 2-alkoxypropenals with 2-mercaptoethanol at heating (60°C, 3 h) in the presence of acids affords 2-methyl-2,2'-bi(1,3-oxathiolane) even at 2-mercaptoethanol deficit. At the double excess of the latter the 2-methyl-2,2'-bi(1,3-oxathiolane) was obtained in quantitative yield. The presumable schemes of conversion of 2-hydroxy-3-alkoxy-3-methyl-1,4-oxathiane into 2-methyl-2-formyl-1,3-oxathiolane and 2-acetyl-1,3-oxathiolane are discussed.     

Propellanes—XXXIV : Electrophilic reactions of propellanes: attack by carbethoxycarbene

The configurations of mono- and bis- adducts obtained on reaction of 3 and 20, respectively, with ethyl diazoacetate in the presence of copper sulfate, were determined. Attack anti- to the imide ring is greater than that syn- to it.     

Reaction of dialkylboric anhydrides with 2-amino- and 2-hydroxypyridine

Conclusions The anhydrides of dialkylboric acids react with 2-aminopyridine at 150–190° and with 2-hydroxypyridine at 100–170° to give cyclic coordination compounds of boron and saturated hydrocarbons.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1919–1921, August, 1977.     

活性氮与SO2和SOCl2的传能反应

在流动余辉装置上, 研究了活性氮与SO2和SOCl2之间的反应过程. 在280～500 nm, 观察到了SO2( A1A2,B1B1→X1A1 )和SO2(a3B1→X1A1)的发射光谱. 对比由Ar(3P0,2)与N2碰撞反应产生的纯N2(A3Σu+)与SO2、SOCl2之间反应的实验结果, 可以说明, N2(A3Σu+)在活性氮与SO2的反应中是主要的能量载体, 它与SO2的直接能量转移反应形成了激发态的SO2(A1A2, B1B1); 在活性氮与SOCl2的反应中观测到的激发态SO2(a3B1), 则可能主要是通过N(4S)与SOCl2反应生成的N2O(X1Σ+)和N2(A3Σu+)与SOCl2反应生成的SO(X3Σ－)之间的化学反应过程产生.     

Reaction of 2-alkenylthiobenzimidazoles with iodine

The reaction of 2-allylthiobenzimidazole and 2-allylthio-1-methylbenzimidazole with iodine leads to the formation of dihydrothiazolo[3,2-a]benzimidazolium systems.Chelyabinsk State University, 454136 Chelyabinsk, Russian. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1130–1132, August, 1997.     

Reaction of 2-hydrazinoperimidine with acetylacetone

Heating 2-hydrazinoperimidine ( 2 ) with acetylacetone in absolute ethanol gave exclusively 2-(3,5-dimethyl-1-pyrazolyl)perimidine ( 4 ) via a [2 + 3] cyclization. The possible [4 + 3] condensate, 3,5-dimethyl-1H-1,2,4-triazepino[4,3-a]perimidine ( 5 ) was not produced. Spectral analyses were applied to the structure elucidation of the products.     

Reaction of 2-aminobenzimidazole with acetylene

The reaction of 2-aminobenzimidazole (1) with acetylene under pressure proceeds with the formation of vinyl monomers, corresponding to amine and imine forms, 1-vinyl-2-amino- and 1,3-divinyl-2-iminobenzimidazoles, depending on the reaction conditions. 1,3-Divinyl-2-benzimidazolone was also isolated in aqueous dioxane in addition to the monovinyl derivative of1. Cyclization of the divinyl derivative of1 with acetylene proceeds to give 9-vinyl-1,2-dimethylimidazo[1,2-a]-benzimidazole.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 664033 Irkutsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 749–751, March, 1992.     

Reaction of 2-Methylenenorbornane with N-Bromosuccinimide

The reaction of 2-methylenenorbornane with N-bromosuccinimide produced a mixture of six monobromides in an overall yield of about 60%. By irradiation in the presence of benzoyl peroxide exo- and endo-3-bromo-2-methylenenorbornanes, 2-bromomethylnorborn-2-ene, Z- and E-2-bromomethylenenorbornanes and 1-bromomethylnortricyclene were found in a percentage ratio of 43.0, 7.5, 6.5, 19.0, 19.0 and 5.0. Without benzoyl peroxide, in the dark, the same products were obtained, but in a percentage ratio of 23.0, 3.0, 17.0, 26.0, 26.0 and 7.0. These results are rationalized in terms of an ionic mechanism in concurrence with some radical mechanism contribution.     

Reaction of 2-Benzothiazolethione with C-Ethoxycarbonyl-N-phenylnitrilimine

Russian Journal of Organic Chemistry -     

Reaction of diethylchlorophosphine with 2-methyloxetane

Conclusions A study was made of the reaction of diethylchlorophosphine with 2-methyloxetane. The isomerization of the-methyl -chloropropyl ester of diethylphosphinous acid goes via the formation of a cyclic intermediate product.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 197–198, January, 1972.     

Reaction of ethyldichlorophosphine with 2-methyloxetane

Conclusions The reaction of ethyldichlorophosphine with 2-methyloxetane was studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 548–550, March, 1972.     

Reaction of 2-methylphenylsulfuranylidenedimedon with sulfides

Conclusions Dibenzyl sulfide and methyl benzyl sulfide demethylate and transylidate 2-methylphenylsulfuranylidenedimedon, in which connection the demethylation predominates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1893–1895, August, 1979.The authors express their gratitude to R. G. Gainullina for taking the PMR spectra.     

Reaction of 2-chloromethylphenols with enaminones

The reaction of o-(chloromethyl)phenols with enamino ketones afforded a series of 3-acyl- and 3-formyl-4H-chromenes as a result of cascade transformation including [4 + 2]-cycloaddition of enamino ketone to o-quinone methide generated in situ and subsequent elimination of secondary amine.