Reaction of trifluororacemic acid methyl ester with 1,3-dienes

The reaction of trifluororacemic acid with 1,3-dienes affords Diels-Alder reaction products in a high yield and with a high degree of specificity. Catalysis by SnCl₄ changes the course of the reaction of the ester with isoprene, affording an ene reaction product.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 141–145. January, 1991.     

Reaction of 2-thiopyrrolidones with monochloroacetic acid and its methyl ester

Calculations of the electronic structure of 5-alkyl-2-thiopyrrolidones and their oxygen analogs were carried out by the MO LCAO method in the CNDO/2 approximation. The obtained data were used to discuss the reactivity of the investigated compounds in the alkylation of monochloroacetic acid, leading, in the case of 2-thiopyrrolidones, to the formation of the corresponding thiazolinones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1690–1692, December, 1986.     

Reaction of oxiranecarbonitrile with L-cysteine methyl ester

The title reaction yields (3R,5R) and (3R,5S) isomers of methyl 5-cyanotetrahydro-1,4-2H-thiazine-3-carboxylate, together with methyl 2-acetylthiazole-4-carboxylate as a minor by-product. The stereochemistry of the tetrahydrothiazine derivatives is discussed.     

Reactions of abietic acid methyl ester with m-chloroperbenzoic acid

Abietic acid methyl ester reacts regioselectively with m-chloro-perbenzoic acid, in the presence of water to yield a mixture of the two epimeric 13,14-monoepoxides. These epoxides further react affording a mixture of 1,2- and 1, 4-unsaturated diols, The overall yield of the reaction is acceptably good (70–80%). The formation of these and other products are discussed.     

Reaction of tetramethyldihydrodisiloxane with chloral hydrate

Conclusions Tetramethyldihydrodisiloxane reacts with chloral hydrate, giving trichloroethyl alcohol in a high yield; the reaction is convenient for preparative purposes. In the presence of PdCl₂ or H₂PtCl₆, the main product is chloroform.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2767–2770, December, 1976.The authors thank G. A. Razuvaev for his constant interest in the paper, valuable advice, and critical comments.     

Reaction of dithiomalonic acid dianilide with methyl propiolate

Dithiomalonic acid dianilide reacted with methyl propiolate in acetic acid in the presence of excess perchloric acid to give 4-anilino-2-methoxycarbonylmethyl-1,3-dithiine-6-phenyliminium perchlorate.     

Reaction of chloral hemiacetals with vinyl ethers

Russian Chemical Bulletin -     

Reaction of o-diaminoanthraquinones with acetoacetic ester and crotonic acid

The reaction of 1,2 (and 2,3)-diamino-9,10-anthraquinones with acetoacetic ester and crotonic acid gave dihydro- and tetrahydroanthraquinonediazepinones, the structures of which were established on the basis of spectral data and chemical transformations.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1107–1112, August, 1982.     

Total synthesis of stephanotic acid methyl ester

[structure: see text]The methyl ester of the naturally occurring macrocyclic pentapeptide stephanotic acid, containing an unusual beta-substituted alpha-amino acid with a tryptophan C-6 to leucine beta-carbon link, has been synthesized. The key steps include the formation of this amino acid through a thioxo-oxazolidine intermediate and a Horner-Wadsworth-Emmons reaction using a phosphonoglycine, derived by a dirhodium(II)-catalyzed N-H insertion reaction, to give a dehydroamino acid and subsequent rhodium(I)-catalyzed asymmetric hydrogenation to introduce the modified tryptophan residue.     

Hydrogenation of 2,4-hexadienoic acid methyl ester

Hydrogenation of 2,4-hexadienoic acid methyl ester on supported metal catalysts (Pd/C, Pt/C, Rh/C and Ru/C) has been investigated. Methyl esters of 2-hexenoic and 3-hexenoic acids were formed and further hydrogenated to the methyl ester of hexanoic acid. Palladium was found to be the most active and selective catalyst for this reaction owing to the formation of intermediates.     

Reaction of the N,N-dimethylamide and methyl ester of 3-phenyl-3-chloro-2-ketopropionic acid with triphenylphosphine

Conclusions The dimethylamide of 3-phenyl-3-chloro-2-ketopropionic acid reacts with Ph₃P to give -(N,N-dimethyloxamoyl)benzyltriphenylphosphonium chloride. In the presence of methanol, this reaction gives dimethyl(phenylpyruvoyl)amide and Ph₃PO.2. The methyl ester of 3-phenyl-3-chloro-2-ketopropionic acid reacts with Ph₃P to give methoxycarbonylstyryloxytriphenylphosphonium chloride, which, upon heating in benzene at reflux, gives methyl -chlorocinnamate and Ph₃PO.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1395–1396, June, 1989.     

Reaction of prostacyclin methyl ester with benzenesulfenyl chloride preparation of stable prostacyclin analogs

Several phenyl sulfides including stable 5- and 7-phenylthioprostacyclins were obtained by the reaction of the vinyl ether ($\text{1}$) and prostacyclin methyl ester ($\text{5}$) with PhSCl.     

Reaction of tetracyclone with the ethyl ester of phenylphosphonous acid

Conclusions Ethyl phenylphosphonite in the presence of triethylamine is added at the carbonyl group of tetracyclone with the formation of -hydroxyphosphinate, which upon heating is converted to products which are identical to the products of 1,6- and 1,4-addition to a conjugated system of tetracyclone; in the presence of a base only the 1,6-addition occurs.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No, 6, pp. 1345–1348, June, 1979.