Reaction of Zinc Enolates Formed from 1-Aryl-2,2-dibromoalkanones and Zinc,with Substituted 2-Oxochromene-3-carbohydrazides

Zinc enolates formed from 1-aryl-2,2-dibromoalkanones and zinc react with N′-methyl-N′-phenyl- and N′-benzylidene-N-phenylhydrazides of 2-oxochromene-3-carboxylic acid to form the corresponding hydrazides of 1-alkyl-1-aroyl-2-oxo-1a,7b-dihydrocyclopropa[c]chromene-1a-carboxylic acid as a single geometric isomer.     

Reactions of Zinc Enolates Derived from 1-Aryl-2,2-dibromoalkanones with 3-Acetyl-6-bromochromen-2-one

Zinc enolates derived from substituted 1-aryl-2,2-dibromoalkanones react with 3-acetyl-6-bromochromen-2-one to give 1a-acetyl-1-alkyl-1-aroyl-6-bromo-1a,7b-dihydro-1H-cyclopropa[c]chromen-2-ones as a single stereoisomer.     

Cyclopropanation of Alkyl and Aryl 3-Aryl-2-cyanopropenoates with Bromine-containing Zinc Enolates Obtained from 1-Aryl-2,2-dibromoalkanones and Zinc

Zinc enolates prepared from 1-aryl-2,2-dibromoalkanones and zinc react with alkyl and aryl 3-aryl-2-cyanopropenoates affording alkyl and aryl 2-alkyl-3-aryl-2-aroyl-1-cyanocyclopropane-1-carboxylates.     

Reformatsky Reaction with N-Substituted 6-Bromo-2-oxochromene-3-carboxamides

Reformatsky reactions of ethyl -bromopropionate, methyl -bromobutyrate, and methyl -bromo-isobutyrate with N-substituted 6-bromo-2-oxochromene-3-carboxamides in the system diethyl ether–benzene– HMPA give N-benzyl-6-bromo-4-(1-alkoxycarbonylalkyl)-2-oxochroman-3-carboxamides, while in the system diethyl ether–benzene–HMPA–THF, 3-R¹-1-R²-1-R³-9-bromo-2,3,4,4a,5,10b-hexahydro-1H-chromeno[3,4-c]-pyridine-2,4,5-triones are obtained.     

Reactions of 1-Aryl-2,2-dibromobutan-1-ones with Zinc and Alkyl 6-Bromo-2-oxo-2-H-chromen-3-carboxylate

Zinc enolates formed from 1-aryl-2,2-dibromobutan-1-ones and zinc react with alkyl 6-bromo-2-oxo-2-H-chromen-3-carboxylates affording alkyl 1-aroyl-6-bromo-2-oxo-1-ethyl-1,7b-dihydrocyclopropa[c]-chromen-1a(2H)-carboxylates as a single isomer.     

Reaction of Zinc Enolates Formed from 1-Aryl-2,2-dibromoalkanones and Zinc,with Aryl Esters and Chloride of 2-Oxo-2<Emphasis Type="Italic">H</Emphasis>-chromene-3-carboxylic Acid

Zinc enolates formed from 1-aryl-2,2-dibromoalkanones and zinc react with 2-oxo-2H-chromene-3-carboxylates to give aryl 1-alkyl-1-aroyl-2-oxo-1a,7b-dihydro-1H-cyclopropa[c]chromene-1a-carboxylates as a single geometric isomer. The reaction of the same zinc enolates with 2-oxo-2H-chromene-3-carboxyl chloride to form 2-bromo-1-arylalkenyl 1-alkyl-1-aroyl-2-oxo-1,7b-dihydro-1H-cyclopropa[c]chromene-1a-carboxylates.     

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.     

Cyclopropanation of 3-(2-Oxo-2<Emphasis Type="Italic">H</Emphasis>-chromen-3-yl-carbonyl)-2<Emphasis Type="Italic">H</Emphasis>-chromen-2-one with Zinc Enolates Derived from 1-Aryl-2,2-dibromoalkanones

Zinc enolates derived from 1-aryl-2,2-dibromoalkanones react with 3-(2-oxo-2H-chromen-3-ylcarbonyl)-2H-chromen-2-one to give 1-alkyl-1-aroyl-1a-(2-oxo-2H-chromen-3-ylcarbonyl)-1a, 7b-dihydrocyclopropa[c]-chromen-2(1H)-ones as a single stereoisomer.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 131–133.Original Russian Text Copyright © 2005 by Shchepin, Russkikh, Uzun, Silaichev.     

Reaction of organozine reagents derived from dialkyl 2,2-dibromomalonates and methyl 4,4-dibromo-3-oxoalkanoates with 2-oxochromene-3-carboxamides

Organozinc compounds obtained by treatment of dialkyl 2,2-dibromomalonates with zinc reacted with N-substituted 2-oxochromene-3-carboxamides to give dialkyl 1a-R-carbamoyl-2-oxo-1a,7b-dihydro-2H-cyclopropa[c]chromene-1,1-dicarboxylates or alkyl 2-R-1,3,4-trioxo-2,3-dihydro-1H,9bH-chromeno[3′,4′:1,3]-cyclopropa[1,2-c]pyrrole-9c-carboxylates. Reactions of N-substituted 2-oxochromene-3-carboxamides with zinc enolates derived from methyl 4,4-dibromo-3-oxoalkanoates led to the formation of the corresponding 9c-alkyl-2-R-2,3-dihydrochromeno[3′,4′:1,3]cyclopropa[1,2-c]pyrrole-1,3,4-triones.     

Reactions of Zinc Enolates of Substituted 1-Aryl-2,2-dibromobutanones with Alkyl Esters of 3-Oxo-3H-benzo[f]chromene-2-carboxylic Acid

Zinc enolates derived from substituted 1-aryl-2,2-dibromobutanones react with alkyl 3-oxo-3H-benzo[f]chromene-2-carboxylates to form alkyl 1-aroyl-1-ethyl-2-oxo-1,9c-dihydro-3-oxacyclopropa[c]phenanthrene-1a-carboxylate as a single geometric isomer.     

Reformatsky reaction of methyl 1-bromocyclohexane-1-carboxylate with N-aryl-2-oxochromene-3-carboxamides

Reformatsky reagent generated from methyl 1-bromocyclohexane-1-carboxylate reacted with N-aryl-2-oxochromene-3-carboxamides and N-aryl-6-bromo-2-oxochromene-3-carboxamides to give, depending on the conditions, the corresponding N-aryl-(6-bromo)-4-(1-methoxycarbonylcyclohexyl)-2-oxochroman-3-carboxamides or 3-aryl-(9-bromo)-1,1-pentamethylene-2,3,4,4a,5,10b-hexahydro-1H-chromeno[3,4-c]pyridine-2,4,5-triones. The products were isolated as a single diastereoisomer.     

Reactions of Zinc Enolates Formed from 1-Aryl-2-bromo-2-phenylethanone or 2-Bromoindanone and Zinc,with Dimethyl 2-(1-Arylmethylene)malonates

Zinc enolates formed from 1-aryl-2-bromo-2-phenylethanones and zinc react with dimethyl 2-(1-arylmethylene)malonates to afford dimethyl 2-(1,3-diaryl-3-oxo-2-phenylpropyl)malonates. The latter react with cyclohexylamine, piperidine, or morpholine to give the corresponding monosubstituted amides. The zinc enolate derived from 2-bromoindanone and zinc reacts with dimethyl 2-(4-bromobenzylidene)malonate, yielding dimethyl 2-[(4-bromophenyl)(1-oxoindan-2-yl)methyl]malonate. The final products largely form as a single diastereomer.     

Azines and azoles: CXXIV. New synthesis of 2-oxochromene-3-carboxamides

2-Aryl-4-hydroxy-6H-1,3-thiazin-6-ones react with substituted 2-hydroxybenzaldehydes in polar solvents to give N-arylcarbothioyl-2-oxochromene-3-carboxamides in 60–70% yield.     

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).     

Reactions of Sodium Enolates Derived from 6-Aryl-3,5,5-trimethyl-2,3,5,6-tetrahydropyrane-2,4-diones with Substituted Benzenesulfonyl Chlorides and Arenediazonium Salts

Sodium enolates derived from 6-aryl-3,5,5-trimethyl-2,3,5,6-tetrahydropyrane-2,4-diones react with substituted benzenesulfonyl chlorides to give the corresponding O-sulfonation products, 6-aryl-4-(4-R-phenylsulfonyloxy)-3,5,5-trimethyl-5,6-dihydropyrane-2-ones. Reactions of the title compounds with arenediazonium tetrafluoroborates afford 6-aryl-3-arylazo-3,5,5-trimethyl-2,3,5,6-tetrahydropyran-2,4-diones as mixtures of syn and anti isomers.     

Reaction of Zinc Enolates of Alkyl Esters of Substituted 4-Bromo-3-Oxoalkanoic Acids with Aldehydes

Zinc enolates formed from ethyl 4-bromo-2,2,4-trimethyl-3-oxopentanoate react under the conditions of one- of two-stage synthesis with aliphatic, unsaturated, or aromatic aldehydes to form 6-R-2,2,4,4-tetramethyl-2,3,5,6-tetrahydropyran-2,4-diones. Zinc enolates obtained from ethyl 4-bromo-2,2-dimethyl-3-oxopentanoate, -hexanoate, and -2,2,5-trimethyl-3-oxohexanoate under the similar conditions react with aliphatic or aromatic aldehydes to give mainly 5-R¹-6-R²-3,3-dimethyl-2,3,5,6-tetrahydropyran-2,4-diones as E or Z isomers or their mixtures. Zinc enolates generated from the ethyl 4-bromo-2,2-diethyl- or 2-benzyl-2-ethyl-3-oxobutanoates react with aromatic aldehydes to give ethyl 5-R-2-R-2-ethyl-3-oxo-4-pentenoates as E isomers.     

Regioselective Alkylation of Lithium Enolates Derived from 2-Heptanone

The benzylation and $\text{u}$-butylation of the kinetic enolate mixture derived from 2-heptanone has been studied in DME in the absence and in the presence of lithium ion complexing agents (triglyme, benzo-14-crown-4, DMF (neat), DMF, and HMPA).     

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.