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 organozinc reagents prepared from bromomalonic acid esters and zinc with 3-aryl-2-cyanopropenoic acid primary amides

Organozinc compounds prepared from bromomalonic acid esters and zinc react with 3-aryl-2-cyanopropenoic acid primary amides giving a single diastereomer of the corresponding 1-R′-4-aryl-2,6-dioxo-5-cyanopiperidine-3-carboxylic acid esters, or 3-R′-6-aryl-2,4-dioxo-5-cyano-3-azabicyclo[3.1.0]hexene-1-carboxylic acid esters.     

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.     

Synthesis of 4,6-diaryl-1-benzyl-6-hydroxy-5,5-dimethyl-2-oxopiperidine-3-carbonitriles and their analogs via a modified Reformatsky reaction

Organozinc compounds obtained from 1-aryl-2-bromo-2-methylpropanone and zinc react with N-benzyl-3-aryl-2-cyanoacrylamides or N-[6-(2-cyano-1-oxo-3-phenylprop-2-enylamino)hexyl]-2-cyano-3-phenylacrylamide to give 4,6-diaryl-1-benzyl-6-hydroxy-5,5-dimethyl-2-oxopiperidine-3-carbonitriles or 1,6-bis(6-aryl-3-cyano-6-hydroxy-5,5-dimethyl-2-oxo-4-phenylpiperidyl)hexanes as a single isomer with trans-located piperidine hydrogen atoms.     

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.     

Spiro heterocyclization of 4,5-diaroyl-2,3-dihydro-1H-pyrrole-2,3-diones with ethyl 3-amino-3-phenylprop-2-enoate

Russian Journal of Organic Chemistry -