- Reaction of methyl 1-bromocycloalkanecarboxylates with zinc and benzoin
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The Reformatsky reagents derived from methyl 1-bromocyclohexane-or 1-bromocyclopentanecarboxylate and zinc add to benzoin to afford the corresponding 4-hydroxy-3,4-diphenyl-2-oxaspiro[4.5]decan-1-one and 4-hydroxy-3,4-diphenyl-2-oxaspiro[4.4]nonan-1-one.
- Kirillov,Slepukhin,Nikiforova,Vasyanin,Shurov
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- Reformatsky Reaction of 1-Aryl-3-(2-hydroxyphenyl)prop-2-en-1-ones with Methyl 1-Bromocyclohexanecarboxylate
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Abstract: 1-Aryl-3-(2-hydroxy-5-R-phenyl)prop-2-en-1-ones reacted with the Reformatsky reagent derived from methyl 1-bromocyclohexanecarboxylate to give 4-(2-aryl-2-oxoethyl)-6-R-2H,4H-spiro[[1]benzopyran-3,1′-cyclohexan]-2-ones. The products are formed as a result of intramolecular cyclization of the adduct of the organozinc reagent and substituted chalcone via nucleophilic attack of the phenoxide oxygen atom on the ester carbonyl carbon atom. No cyclization products resulting from attack of the enolate oxygen atom on the ester carbonyl carbon atom were detected.
- Nikiforova,Baibarodskikh,Kirillov,Dmitriev,Zverev
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p. 2074 - 2078
(2021/02/09)
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- Iridium(I)-catalyzed vinylic C-H borylation of 1-cycloalkenecarboxylates with bis(pinacolato)diboron
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Ir(i)-catalyzed C-H borylation of 1-cycloalkenecarboxylic derivatives with bis(pinacolato)diboron affords various alkenylboronates with functional groups in excellent yields. This reaction was also used in a one-pot borylation/Suzuki-Miyaura cross-coupling procedure.
- Sasaki, Ikuo,Doi, Hana,Hashimoto, Toshiya,Kikuchi, Takao,Ito, Hajime,Ishiyama, Tatsuo
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p. 7546 - 7548
(2013/08/23)
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- Synthesis and some reactions of 1-(trimethoxymethyl)cyclohexene
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1-(Trimethoxymethyl)cyclohexene (11) was synthesized in three steps from N-methyl-N-phenylcyclohex-1-ene-1-carboxamide (8). Reaction of the α,β-unsaturated ortho ester (11) with sodium hydride and N-methylaniline gave a 1:1 mixture of methyl cyclohex-1-ene-1-carboxylate (15) and N,N-dimethylaniline. Treatment of (11) with 3-methoxyphenol gave 1-[dimethoxy(3′-methoxyphenoxy)methyl]cyclohexene (10) which underwent thermolysis at 250° to give 1,3-dimethoxybenzene (16) and methyl cyclohex-1-ene-1-carboxylate (15).
- Bourke, David G.,Collins, David J.
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p. 1287 - 1291
(2007/10/03)
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- Preparation of 2,2-Dihalocarboxylic Acid Methyl Esters by Oxidation-Chlorination of 2-(1-Haloalkyl)-4-methyl-1,3-dioxolanes with Trichloroisocyanuric Acid
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Methyl 2,2-dichloro or 2-bromo-2-chloro carboxylates were obtained in excellent yields by oxidation-chlorination of 2-(1-haloalkyl)-4-methyl-1,3-dioxolanes with trichloroisocyanuric acid.
- Boni, Monica,Ghelfi, Franco,Pagnoni, Ugo Maria,Zucchi, Claudia
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p. 1622 - 1626
(2007/10/02)
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- Hydrocarbonylating Cyclization of Dienes, 6. - Metal-Induced Skeletal Rearrangements during an Attempted Synthesis of the Acorane System from Substituted 1,1-Divinylcyclohexanes
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In attempts of a regio- and stereoselective synthesis of the acorane skeleton 2, substituted 1,1-divinylcyclohexanes 1 were treated under the conditions of hydrocarbonylating cyclization.Substrates with higher degree of substitution surprisingly did not l
- Eilbracht, Peter,Acker, Michael,Huettmann, Gerd,Winkels, Irmgard
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p. 159 - 168
(2007/10/02)
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- Improved Preparation of Methyl 3-Oxo-1-cyclohexene-1-carboxylate and Its Use in the Synthesis of Substituted 1,5-Cyclodecadienes
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An improved preparation of methyl 3-oxo-1-cyclohexene-1-carboxylate (6) is reported in which cyclohexanecarboxylic acid is converted to methyl 1-bromocyclohexanecarboxylate by a variation of the Hell-Volhard-Zelinsky reaction and then the bromo ester is dehydrohalogenated with quinoline and the resultant unsaturated ester is oxidized at an allylic position with chromium trioxide in acetic acid and acetic anhydride to give 6.The overall conversion proceeds in 49percent yield, which is a substantial improvement over previous attempts reported for this sequence.Photoadditionof 6 and cyclobutene-1-carboxylic acid yields adduct 8, which after esterification and thermolysis gives the 1,5-cyclodecadiene 12.In addition, reduction of adduct 8 with NaCNBH3 followed by spontaneous lactoniaztion yields 10, which upon thermolysis gives the lactone diene 11.This approach should have applications in the synthesis of germacranolides that have an ester or related carbonyl function on C(14).
- Lange, Gordon L.,Otulakowski, John A.
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p. 5093 - 5096
(2007/10/02)
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