V. A. Egorov

Reaction of 5-Allyl-2,3,5-trichloro-4,4-dimethoxycyclopent-2-en-1-one with amino acids

Abstract5-Allyl-2,3,5-trichloro-4,4-dimethoxycyclopent-2-en-1-one reacts with L-proline and L-methionine methyl esters to give diastereoisomeric mixtures of the corresponding chlorine replacement products at C3.

Comparing Two Alternative Pollutant Dispersion Models and Actual Data within an Environmental Health Information Processing System (EHIPS)

This paper presents the test results for an air pollutant dispersion modelling unit working within a larger software system EHIPS designed for environmental health information processing. We start with the description of the whole system and then proceed to the modelling unit, which uses two standard dispersion models - one Russian (OND-86) and one American (ISC3ST). The peculiarity of this unit is just in its links to other components of the system, which opens the way to multifold usage of the modelling results, including easy comparison between the model and the data obtained from actual measurements.

Reaction of hexachlorobutadiene with sodium methoxide

Hexachlorobutadiene reacts with MeONa in refluxing methanol to give (Z)-4,4-dimethoxy2-oxobut-3-enoic acid and 2,4,4-trichloro-1,1,1,3-tetramethoxybut-2-ene, which were converted to methyl (Z)-4,4-dimethoxy-2-oxobut-3-enoate and methyl (Z)-2,4,4-trichloro-3methoxybut-2-enoate upon treatment with CH2N2 and acid hydrolysis, respectively.

New chiral dihydroxycyclopropane block from L-tartaric acid

Functionalized hydroxycyclopropane derivatives attract interest as binding units and building blocks in organic synthesis [1, 2]. In this connection, widely used Kulinkovich reaction (transformation of RCO2Me into R-cyclopropanol) should be noted [3]. The present communication reports on the synthesis of a new chiral dihydroxycyclopropane derivative I with the use of accessible L-tartaric acid as source of chirality. The scheme of synthesis of compound I includes the following steps. Reduction of known L-tartaric acid dimethyl ester acetonide II [4] with sodium tetrahydridoborate gave alcohol III in a moderate yield [5]. Compound III was converted first into p-toluenesulfonate IV and then into bromide V. The latter underwent intramolecular cyclization to produce target product I by the action of hexamethyldisilazane sodium salt in THF (yield ~60%).

Convenient synthesis of 5-benzyl-2,3,5-trichloro-4,4-dimethoxycyclopent-2-en-1-one and some its reactions

Abstract5-Benzyl-2,3,5-trichloro-4,4-dimethoxycyclopent-2-en-1-one was synthesized by reaction of 1,2,3,4-tetrachloro-5,5-dimethoxycyclopentadiene with benzyl alcohol in methylene chloride in the presence of powdered sodium hydroxide and benzyltrimethylammonium chloride as phase-transfer catalyst. Deprotection of the title compound gave 2-benzyl-2,4,5-trichlorocyclopent-4-ene-1,3-dione which was subjected to unusual intramolecular carbocyclization initiated by molecular iodine.

Some reactions of 5-benzyl-2,3,5-trichloro-4,4-dimethoxy-cyclopent-2-en-1-one and its derivatives

Abstract5-Benzyl-2,3,5-trichloro-4,4-dimethoxycyclopent-2-en-1-one and 2-benzyl-2,4,5-trichlorocyclopent-4-ene-1,3-dione were subjected to dehydrochlorination by the action of 1,4-diazabicyclo[2.2.2]octane, selective dechlorination at C5 by the action of CrCl2, and AdNE replacement of the chlorine atom at C3 by the action of secondary amines. The reduction of 2-benzyl-2,4-dichloro-5-morpholinocyclopent-4-ene-1,3-dione with sodium tetrahydridoborate in methanol and ethanol gave different products.

New functionalized pyrrolidines

New functionalized pyrrolidines have been synthesized from accessible amino acids by the [C+NC+CC]-coupling reaction.

Reaction of fullerene C60 with methyl (2Z)-2,4,4-trichloro-3-methoxybut-2-enoate

Synthesis of functionalized fullerenes is an important line in searching for promising compounds and materials for pharmacology and optoelectronics [1–3]. We previously used dichloroacetic acid esters 1 to obtain methano derivatives of C60 [4, 5]. Compounds 1 contain an acidic CH proton and readily react with C60 in the presence of bases (DBU) according to Bingel [6]. In order to extend the series of possible cyclopropanation reagents with an activated CHCl2 group, we examined the reaction of C60 with methyl (Z)-2,4,4-trichloro-3-methoxybut-2-enoate (2) [7]. at 20°C (~6 h), and it smoothly afforded the corresponding monoadduct as the major product, as well as some amounts of diand polyaddition products. To minimize side formation of polyadducts, the reaction was terminated at incomplete conversion of C60, and monoadduct 4 was isolated in 52% yield by column chromatography on silica gel. The amount of unreacted fullerene was about 30%. ISSN 1070-4280, Russian Journal of Organic Chemistry, 2016, Vol. 52, No. 3, pp. 456–457.

Trichlorocyclopentenone conjugates with amino acids. Isolation and structure of diastereomerically pure N-[(4R)-4-allyl-2,4-dichloro-5,5-dimethoxy-3-oxocyclopent-1-en-1-yl]-L-methionine methyl ester

N-[(4R)-Allyl-2,4-dichloro-5,5-dimethoxy-3-oxocyclopent-1-en-1-yl)-L-methionine methyl ester has been isolated from the diastereoisomer mixture, and its structure has been proved by X-ray analysis.

Reaction of (2S,3S)-2-benzyloxybutane-1,2,4-triol with N,N′-carbonyldiimidazole

Abstract(2S,3S)-2-Benzyloxybutane-1,2,4-triol reacted with N,N′-carbonyldiimidazole to give a mixture of the expected 1,2-carbonate and the corresponding bis-carbonate.