Cyclopropanation of 2-arylmethylidenemalononitriles,alkyl 3-aryl-2-cyanoprop-2-enoates,and N-substituted 3-aryl-2-cyanoprop-2-enamides with bromine-containing zinc enolates

Zinc enolates derived from 2,2-dibromoindan-1-one and 2,2-dibromo-1,2,3,4-tetrahydronaphthalen-1-one reacted with 2-arylmethylidenemalononitriles, alkyl 3-aryl-2-cyanoprop-2-enoates, and N-substituted 3-aryl-2-cyanoprop-2-enamides to give, respectively, 3-aryl-1′-oxo-1′,3′-dihydrospiro[cyclopropane-1,2′-indene]-2-2-dicarbonitriles, 3-aryl-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2,2-dicarbonitriles, alkyl 3-aryl-2-cyano-1′-oxo-1′,3′-dihydrospiro[cyclopropane-1,2′-indene]-2-carboxylates, alkyl 3-aryl-2-cyano-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2-carboxylates, and N-substituted 3-aryl-2-cyanol-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2-carboxamides as a single diastereoisomer. The stereoconfiguration of the products was determined by ¹H and ¹³C NMR spectroscopy.     

Reaction of methyl 1-bromocyclopentane-1-carboxylate with zinc and 3-aryl-2-cyanoprop-2-enamides

Reformatsky reaction of methyl 1-bromocyclopentane-1-carboxylic acid with 3-aryl-2-cyanoprop-2-enamides and their N-methyl derivatives afforded 10-aryl-6,8-dioxo-7-azaspiro[4.5]decane-9-carbonitriles and 10-aryl-7-methyl-6,8-dioxo-7-azaspiro[4.5]decane-9-carbonitriles, respectively.     

Reaction of methyl esters of substituted 2-oxochromene-3-carboxylic acids with zinc enolates formed from 1-aryl-2-bromoalkanones

Zinc enolates formed from 1-aryl-2-bromoalkanones react with methyl esters of substituted 2-oxochromene-3-carboxylic acids to give methyl esters of 6-bromo- or 6,8-dibromo-4-(2-aryl-2-oxo-1-R- ethyl)-2-oxochromane-3-carboxylic acids as mixtures of two diastereomers.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 9, 2004, pp. 1520–1523.Original Russian Text Copyright © 2004 by Shchepin, Korzun, Shurov, Vakhrin, Russkikh.This revised version was published online in April 2005 with a corrected cover date.     

Reaction of Zinc Enolates Derived from Substituted 2,2-Dibromobutyrophenones with Ethyl 5,5-Dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylate

Zinc enolates derived from substituted 2,2-dibromobutyrophenones react with ethyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylate to give ethyl 6-aroyl-6-ethyl-4,4-dimethyl-2-oxo-3-oxabicyclo[3.1.0]-hexane-1-carboxylates mostly as a single geometric isomer.     

Reaction of alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates with zinc enolates prepared from zinc and 1-arul-2-bromo-2-phenylethanones, 2 bromoindanone, and 2-bromo-6-methyltetralone

Alkyl 5,5-dimethyl-2-oxo-2,5-dihydrofuran-3-carboxylates react with zinc enolates prepared from 1-aryl-2-bromo-2-phenylethanones, 2-bromo indanone, 2-bromo-6-methyltetralone and zinc with formation of ethyl 4-(2-aryl-2-oxo-1-phenyl-ethyl)-5,5-dimethyl-2-oxotetrahydrofuran-3-carboxylates, alkyl 5,5-dimethyl-2-oxo-4-(1-oxoindan-2-yl)tetrahydrofuran-3-carboxylates, and ethyl 5,5-dimethyl-4-(6-methyl-1-oxo-1,2,3,4-tetrahydronaphthalen-2-yl)-2-oxotetrahydrofuran-3-carboxylates respectively, mainly as single diastereomers.     

Reactions of organozinc reagents derived from dialkyl 2,2-dibromomalonates with 3-aryl-2-cyanoprop-2-enamides

Organozinc compounds obtained by treatment of dialkyl 2,2-dibromomalonates with metallic zinc reacted with N-substituted 3-aryl-2-cyanoprop-2-enoic acid amides to give alkyl 3-R-6-aryl-5-cyano-2,4-dioxo-3-azabicyclo[3.1.0]hexane-1-carboxamides as a single stereoisomer.     

Reaction of zinc enolates prepared from 2,2-dibromoindan-1-one or 2,2-dibromo-1-tetralone and zinc with 2-oxochromen-3-carboxylic acid derivatives

Zinc enolates obtained from 2,2-dibromonidan-1-one or 2,2-dibromo-1-tetralone and zinc reacted with alkyl esters and amides of 2-oxochromen-3-carboxylic acid giving the corresponding derivatives of 2,1′-dioxo-spiro(1a,7b-dihydrocyclopropa[c]chromen-1,2′-indan)-or 1′,2′,3′,4′-tetrahydro-2,1′-dioxospiro(1a,7b-dihydrocyclopropa[c]chromen-1,2′-naphthalene)-1a-carboxylic acids prevailingly in the form of a single geometric isomer.     

Reactions of zinc enolates derived from 1-aryl-2-bromo-2-phenylethanone and 2-bromoindan-1-one with alkyl 2-oxochromene-and 6-bromo-2-oxochromene-3-carboxylates

Zinc enolates derived from 1-aryl-2-bromo-2-phenylethanone react with alkyl 2-oxochromene-3-carboxylates and methyl 6-bromo-2-oxochromene-3-carboxylate to give, respectively, alkyl 4-(2-aryl-2-oxo-1-phenylethyl)-2-oxochroman-3-carboxylates and methyl 6-bromo-4-(2-aryl-2-oxo-1-phenylethyl)-2-oxochroman-3-carboxylate as a single stereoisomer. Zinc enolates derived from 2-bromoindan-1-one react with alkyl 2-oxochromene-3-carboxylates to give alkyl 2-oxo-4-(1-oxoindan-2-yl)chroman-3-carboxylates as a single stereoisomer.     

Reactions of Ethyl 2-Amino-5-(2-aryl-2-oxoethylidene)- 4-oxo-4,5-dihydrofuran-3-carboxylates and 2-Amino-5-(2-aryl- 2-oxoethylidene)-4-oxo-4,5-dihydrofuran-3-carbonitriles with Alcohols

Ethyl 2-amino-5-(2-aryl-2-oxoethylidene)-4-oxo-1H-4,5-dihydrofuran-3-carboxylates and 2-amino- 5-(2-aryl-2-oxoethylidene)-4-oxo-1H-4,5-dihydrofuran-3-carbonitriles reacted with alcohols in the presence of a catalytic amount of concentrated aqueous HCl to give the corresponding 5-alkoxy-2-amino-5-(2-aryl-2- oxoethyl)-4-oxo-1H-4,5-dihydrofuran-3-carboxylic acid derivatives. A probable reaction mechanism was proposed on the basis B3LYP/6-311G(d) quantum chemical calculations.     

Reaction of the zinc enolate derived from 1,1-dibromo-3,3-dimethylbutan-2-one with 3-aryl-2-cyanopropenoic acid amides and esters and 2-oxochromene-3-carboxamides

Zinc enolate derived from 1,1-dibromo-3,3-dimethylbutan-2-one reacts with 3-aryl-2-cyanoprop-2-enamides and aryl 3-aryl-2-cyanoprop-2-enoates to give the corresponding derivatives of 3-aryl-2-(2,2-dimethylpropanoyl)-1-cyanocyclopropane-1-carboxylic acid as a single stereoisomer with cis arrangement of the hydrogen atoms at the cyclopropane ring. The reactions of the same zinc enolate with 3-morpholinocarbonyl-2H-chromen-2-one and 2-morpholinocarbonyl-3H-benzo[f]chromen-3-one lead to formation of 1-(2,2-dimethylpropanoyl)-1a-morpholinocarbonyl-1a,7b-dihydrocyclopropa[c]chromen-2-one and 1-(2,2-dimethylpropanoyl)-1a-morpholinocarbonyl-1a,9c-dihydrobenzo[f]cyclopropa[c]chromen-2-one, respectively as a single stereoisomer.     

Synthesis and some chemical transformations of N-cyclohexyl-2-imino-4-methyl-5,5-pentamethylene-2,5-dihydrofuran-3-carboxamide

Russian Journal of Organic Chemistry -     

Reaction of 2-Imino-2,5-dihydrofuran-3-carboxamides with Benzaldehyde

Russian Journal of Organic Chemistry - The reaction of 2-imino-2,5-dihydrofuran-3-carboxamides with benzaldehyde in pentan-1-ol in the presence of piperidine gave new dihydrofuran derivatives with...     

Reaction of N-substituted 2-oxochromen-3-carboxamides with bromoderivatives of zinc enolates prepared from alkyl 2,2-dialkyl-4,4-dibromo-3-oxoalkanoates and zinc

Zinc enolates obtained from ethyl 2,2-dialkyl-4,4-dibromo-3-oxobutanoates and zinc react with N-substituted 2-oxochromen-3-carboxamides forming ethyl 3-{1a-(R³-carbamoyl)-2-oxo-1a,7b-dihydrocyclopropa[c]chromen-1-yl}-2,2-dialkyl-3-oxopropanoate isomer with a Z-position of methine hydrogens. Zinc enolates prepared from alkyl 2,2-dialkyl-4,4-dibromo-3-oxopentanoates and-hexanoates and zinc react with N-substituted 2-oxochromen-3-carboxamides to give rise to esters of 3-{1-alkyl-1a-(R³-carbamoyl)-2-oxo-1a,7b-dihydrocyclopropa-[c]chromen-1-yl}-2,2-dialkyl-3-oxopropanoic acid as isomers with the E-position of the methine proton and the alkyl substituent. The reaction carried out in the presence of small quantities of THF and HMPA leads to the formation of 9c-alkyl-2-R³-9b,9c-dihydro-5-oxa-2-azacyclopenta[2,3]-cyclopropa[1,2-a]naphthalene-1,3,4-triones. Zinc enolates from alkyl 2,2-dialkyl-4,4-dibromo-3-oxopentanoates and-hexanoates and zinc with the secondary amides of 2-oxochromen-3-carboxylic acid form alkyl 3-{2-oxo-1a-(piperidinocarbonyl)-and 3-{6-R¹-1a-(morpholinocarbonyl)-2-oxo-1a,7b-dihydrocyclopropa[c]chromen-1-yl}-2,2-R²,R²-3-oxopropanoates as single geometrical isomers.     

Reactions of zinc enolates derived from 1-aryl-2,2-di-bromoalkanones with 2-acyl-3H-benzo[f]chromen-3-ones, 6-bromo-2-oxochromene-3-carboxamides, and 3-oxo-3H-benzo-[f]chromene-2-carboxamides

Zinc enolates derived from substituted 1-aryl-2,2-dibromoalkanones reacted with 2-acyl-3H-benzo-[f]chromen-3-ones to give 1-alkyl-1-aroyl-1a-acyl-1a, 9c-dihydro-1H-3-oxacyclopropa[c]phenanthren-2-ones which were formed as a single stereoisomer. Reactions of the same zinc enolates with 6-bromo-2-oxo-chromene-3-carboxamides (piperidides and morpholides) afforded 1-aroyl-6-bromo-1-alkyl-1a-piperidino-(morpholino)carbonyl-1a,7b-dihydrocyclopropa[c]chromen-2-ones with high stereoselectivity. Likewise, 1-benzoyl-1-methyl-1a-morpholinocarbonyl-1a, 9c-dihydro-1H-3-oxacyclopropa[c]phenanthren-2-one was obtained by reac-tion with 3-oxo-3H-benzo[f]chromene-2-carboxylic acid morpholide.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1399–1404.Original Russian Text Copyright © 2004 by V. Shchepin, Kalyuzhnyi, Silaichev, Russkikh, R. Shchepin, Ezhikova, Kodess.This study was performed under financial support by the Russian Foundation for Basic Research (project no. 04-03-96 036).     

Interaction of decacarbonyldimanganese and decacarbonyldirhenium with 1-aryl-3-cyanoprop-2-en-1-ones

The reactions of M₂(CO)₁₀ (M = Mn, Re) withtrans-1-aryl-3-cyanoprop-2-en-1-ones in the presence of Me₃NO proceed with replacement of the CO ligand and lead to complexeseq-(1-aryl-3-cyanoprop-2-en-1-on)nonacarbonyldimanganese andeq-(1-aryl-3-cyanoprop-2-en-1-on)nonacarbonyldirhenium complexes where the metals are bonded with the ligand through the nitrogen atom of the cyanogroup. The treatment of (1-phenyl-3-cyanoprop-2-en-1-on)nonacarbonyldirhenium with a second equivalent of the ligand resulted in the disubstituted complex,eq,eq-bis(1-phenyl-3-cyanoprop-2-en-1-on)octacarbonyldirhenium in a good yield. The structures of the obtained complexes are discussed on the basis of¹³C,¹H NMR, and IR-spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1485–1487, August, 1994.This work was supported in part by the Russian Foundation for Basic Research (grant No 93-03-4028).     

Ring Opening of 4-Arylamino-2-tert-butyl-5-oxo-2,5-dihydrofuran-2-yl Acetates with Aromatic and Heterocyclic Amines

Russian Journal of Organic Chemistry - Reactions of 4-arylamino-2-tert-butyl-5-oxo-2,5-dihydrofuran-2-yl acetates with an equimolar amount of aromatic or heterocyclic amine in toluene involves...     

First synthesis of 4-oxo-6-trifluoromethyl-4H-thiopyran-2-carboxylic acid and its derivatives

Treatment of 6-trifluoromethylcomanic acid with sodium hydrosulfide afforded for the first time 4-oxo-6-trifluoromethyl-4H-thiopyran-2-carboxylic acid (6-trifluoromethylthiocomanic acid). When heated or treated with H₂SO₄, this acid easily underwent decarboxylation leading to 2-trifluoromethyl-4H-thiopyran-4-one. Because of this, both ethyl and methyl 6-tri-fluoromethylthiocomanates were obtained in low yields (15–23%). Decarboxylation of 6-tri-(di)fluoromethylcomanic acids gave 2-tri(di)fluoromethyl-4H-pyran-4-ones in 77–80% yields.     

Methanolysis and hydrolysis of derivatives of methyl 2,5- and 4,5-dihydrofuran-2-carboxylates

Methyl 2,5-dimethoxy-2,5-dihydrofuran-2-carboxylate is formed in the reaction of HCl-CH₃OH with methyl 5-nitro-2-acetoxy-2,5-, 5-nitro-4-acetoxy-4,5-, and 2,5-diacetoxy-2,5-dihydrofuran-2-carboxylates, whereas methyl 2,5-dioxo-3-pentenoate bis(2,4-dinitrophenylhydrazone) and 4-oxo-2-penten-1,5-dioic acid 2,4-dinitrophenylhydrazone are isolated in the presence of 2,4-dinitrophenylhydrazine. Methyl 5-nitrofuran-2-carboxylate is formed by treatment of methyl 5-nitro-2-acetoxy-2,5-dihydrofuran-2-carboxylate with aqueous solutions of acetic or phosphoric acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1600–1603, December, 1977.