- Reduction of Cyclopropanecarboxylic Acids by Borane, a Chemoselective Reaction Sensitive to Steric Interactions and Reaction Conditions
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A number of cyclopropanecarboxylic acids have been reduced by borane in tetrahydrofuran to the corresponding cyclopropyl alcohols. The yield was sensitive to the steric influence of the substituents attached to the ring, the reaction temperature, and the
- Sydnes, Leiv K.,Pereira, Paula F. F.,Sandberg, Marcel,Oevreboe, Hans H.
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p. 464 - 474
(2007/10/03)
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- Reactions of the Ethers of 2,2-Dibromo-1-hydroxymethylcyclopropane with Methyllithium. Diastereoselectivity in the Synthesis and Transformations of 2-R-Oxabicyclo[3.1.0]hexanes
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In reactions of the ethers of 2,2-dibromo-1-hydroxymethylcyclopropane with methyllithium predominant formation of derivatives of the endo-2-R-3-oxabicyclo[3.1.0]hexane was observed. The reactions in the first stage yield cyclopropylidenes which subsequent
- Bolesov,Tverezovskii,Grishin
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p. 817 - 829
(2007/10/03)
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- SELECTIVE SYNTHESIS OF γ,δ-UNSATURATED CARBOXYLIC ACID DERIVATIVES BY THE NI(CO)4-INDUCED RING-OPENING CARBONYLATION REACTION
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gem-Dibromocyclopropanes bearing the chloromethyl or mesyloxymethyl substituent at the vicinal position underwent the Ni(CO)4-induced ring-opening carbonylation reaction with alcohol or amines leading to the γ,δ-unsaturated carboxylic acid derivatives sel
- Hirao, Toshikazu,Nagata, Shinichiro,Agawa, Toshio
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p. 5795 - 5798
(2007/10/02)
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- Reactions of 2,2-dibromocyclopropyl carboxylic acids with methyllithium
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For reactions of 2,2-dibromocyclopropyl carboxylic acids with methyllithium, the course reaction depends mainly on the position of the carboxyl group.When the COOH group is directly attached to the gem-dibromocyclopropane ring MeLi generally attacks the gem-dibromo moiety and gives the corresponding monobromocyclopropane as the principal product.When the reaction is performed above -80 deg C the monobromides are formed stereospecifically in the trans configuration.The highest yields, as high as 80-90percent, are obtained 0 deg C.When the carboxyl group is not directly attached to the cyclopropane ring most of the MeLi is consumed in an acid-base reaction with the COOH group.
- Sydnes, Leiv K.,Skare, Soelvi
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p. 2073 - 2078
(2007/10/02)
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- SYNTHESIS, STRUCTURE, AND REACTIVITY OF CYCLOPROPANES AND CYCLOPROPENES. XII. PARTIAL REDUCTION OF 1,1-DIBROMO-2-METHYL-2-CYANO(METHOXYCARBONYL)CYCLOPROPANES
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Functional derivatives (ethers, nitriles, acids, hydrazides, and alcohols) of monohalogenocyclopropane (possible precursors of the corresponding 3,3-disubstituted cyclopropenes) were obtained by partial reduction of the gem-dibromomethylene unit with zinc in alcohol and by the necessary functional modifications in the readily obtainable 1,1-dibromo-2-methyl-2-cyano(methoxycarbonyl)cyclopropanes.The reduction of 1,1-dibromo-2-methyl-2-cyanocyclopropane is highly stereoselective and leads to an easily separated mixture of E- and Z-1-bromo-2-methyl-2-cyanocyclopropanes.
- Latypova, M. M.,Katerinich, L. V.,Baranova, I. N.,Plemenkov, V. V.,Bolesov, I. G.
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p. 2253 - 2257
(2007/10/02)
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