14376-79-5Relevant articles and documents
Nickel-catalysed conjugate addition to trimethylaluminum to sterically hindered α,β-unsaturated ketones
Flemming,Kabbara,Nickish,Neh,Westermann
, p. 317 - 320 (1995)
Nickel acetylacetonate is an efficient catalyst for the 1,4-addition of trimethylaluminum to α,β-unsaturated ketones. The reaction is strongly solvent dependent and gives best results in tetrahydrofuran or ethyl acetate. The reaction is especially useful for the nucleophilic 1,4-methyl transfer to sterically hindered enones. A β-cuparenone synthesis via conjugate methyl group addition to an enone precursor is described.
STREIC EFFECTS ON REACTION RATES II: RATE AND EQUILIBRIUM CONSTANTS FOR OXIDATION OF BICYCLIC ALCOHOLS
Mueller, Paul,Blanc, Jacky
, p. 715 - 718 (1981)
Equilibrium constants for oxidation of a series of bicyclic alcohols with cyclohexanone have been determined under Meerwein-Pondorf conditions.The data provide the thermodynamic background for interpretation of the mechanism of alcohol oxidation and ketone reductions.Free energies of the equilibrium (ΔGox) are compared with values calculated by molecular mechanics.
Enolate-Based Regioselective Anti-Beckmann C-C Bond Cleavage of Ketones
Jahn, Ullrich,Ma?ek, Tomá?
, p. 11608 - 11632 (2021/09/02)
The Baeyer-Villiger or Beckmann rearrangements are established methods for the cleavage of ketone derivatives under acidic conditions, proceeding for unsymmetrical precursors selectively at the more substituted site. However, the fragmentation regioselectivity cannot be switched and fragmentation at the less-substituted terminus is so far not possible. We report here that the reaction of ketone enolates with commercial alkyl nitrites provides a direct and regioselective way of fragmenting ketones into esters and oximes or ω-hydroxyimino esters, respectively. A comprehensive study of the scope of this reaction with respect to ketone classes and alkyl nitrites is presented. Control over the site of cleavage is gained through regioselective enolate formation by various bases. Oxidation of kinetic enolates of unsymmetrical ketones leads to the otherwise unavailable "anti-Beckmann"cleavage at the less-substituted side chain, while cleavage of thermodynamic enolates of the same ketones represents an alternative to the Baeyer-Villiger oxidation or the Beckmann rearrangement under basic conditions. The method is suited for the transformation of natural products and enables access to orthogonally reactive dicarbonyl compounds.
METHOD OF PREPARING 3,3,5,5-TETRAMETHYLCYCLOHEXANONE
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Paragraph 0111, (2013/05/22)
Method of preparing 3,3,5,5-tetramethylcyclohexanone comprising step (i): (i) converting isophorone to 3,3,5,5-tetramethylcyclohexanone in the presence of methylmagnesium chloride. The thus prepared 3,3,5,5-tetramethylcyclohexanone may be employed in a method of preparing 1-amino-1,3,3,5,5-pentamethylcyclohexane (Neramexane) or a pharmaceutically acceptable salt thereof.
METHOD OF PREPARING NERAMEXANE
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Page/Page column 38, (2011/02/24)
Method of producing a salt of 1-amino-1,3,3,5,5-pentamethylcyclohexane comprising steps (i) to (v): (i) converting isophorone to 3,3,5,5-tetramethylcyclohexanone; (ii) converting 3,3,5,5-tetramethylcyclohexanone obtained in step (i) to 1- hydroxy-1,3,3,5,5-pentamethylcyclohexane; (iii) converting 1-hydroxy-1,3,3,5,5-pentamethylcyclohexane obtained in step (ii) to 1-chloroacetamido-1,3,3,5,5-pentamethylcyclohexane; (iv) converting 1-chloroacetamido-1,3,3,5,5-pentamethylcyclohexane obtained in step (iii) to 1-amino-1,3,3,5,5-pentamethylcyclohexane; wherein at least one of 3,3,5,5-tetramethylcyclohexanone, 1-hydroxy-1,3,3,5,5- pentamethylcyclohexane, 1-chloroacetamido-1,3,3,5,5-pentamethylcyclohexane, is not subjected to a purification step.
METHOD OF PREPARING NERAMEXANE
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Page/Page column 40, (2011/02/24)
Method of preparing 1-amino-1,3,3,5,5-pentamethylcyclohexane or a pharmaceutically acceptable salt thereof, comprising at least two steps selected from the following steps (i) to (iv): (i) converting isophorone to 3,3,5,5-tetramethylcyclohexanone in the presence of methylmagnesium chloride; (N) converting 3,3,5,5-tetramethylcyclohexanone to 1-hydroxy-1,3,3,5,5- pentamethylcyclohexane in the presence of methylmagnesium chloride; (iii) converting 1-hydroxy-1,3,3,5,5-pentamethylcyclohexane to 1-chloroacetamido- 1,3,3,5,5-pentamethylcyclohexane in the presence of chloroacetonitrile in acidic solution; (iv) converting 1-chloroacetamido-1,3,3,5,5-pentamethylcyclohexane to 1-amino- 1,3,3,5,5-pentamethylcyclohexane in the presence of thiourea in water.
METHOD OF PREPARING 3,3,5,5-TETRAMETHYLCYCLOHEXANONE
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Page/Page column 18, (2011/02/24)
Method of preparing 3,3,5,5-tetramethylcyclohexanone comprising step (i): (i) converting isophorone to 3,3,5,5-tetramethylcyclohexanone in the presence of methylmagnesium chloride. The thus prepared 3,3,5,5-tetramethylcyclohexanone may be employed in a method of preparing 1-amino-1,3,3,5,5-pentamethylcyclohexane (Neramexane) or a pharmaceutically acceptable salt thereof.
Applications of diethoxymethane as a versatile process solvent and unique reagent in organic synthesis
Boaz, Neil W.,Venepalli, Bhaskar
, p. 127 - 131 (2013/09/07)
Diethoxymethane (DEM) has recently become available in commercial quantities. It has unique properties and is useful in a variety of applications in organic synthesis. It is low boiling (88 °C), azeotropes with water, and has a very low affinity for water. It is stable under basic conditions and as manufactured does not require drying for use as a solvent, even for organometallic reactions. DEM is useful as a process solvent especially for sodium hydride reactions, organolithium chemistry, copper-catalyzed conjugate additions, and phase-transfer reactions. As such, DEM is a potential replacement for tetrahydrofuran (THF), dichloromethane (CH2Cl2), glyme (1,2-dimethoxyethane), and methylal (1,1-dimethoxymethane). DEM is also useful as an ethoxymethylating agent, a formaldehyde equivalent, and a carbonylation substrate. Due to these unique properties and applications, DEM has exciting potential for widespread use both as a reagent and especially as a preferred solvent.
Methylation or ethylation agent and process for 1,4-addition of a methyl or ethyl group to an α, β-unsaturated keto compound
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, (2008/06/13)
This invention describes a new methylation or ethylation agent containing trimethyl aluminum or dimethyl zinc or triethyl aluminum as methyl or ethyl source, which additionally contains catalytic amounts of one or more copper(I) and/or copper(II) compounds as well as a process for the 1,4-addition of a methyl or ethyl group to an α,β-unsaturated or an α,β-double unsaturated ketone or an α,β-unsaturated aldehyde using the agent according to the invention. By using only catalytic amounts of copper and a CKW (chlorinatedhydrocarbon)-free reaction medium, the new methylation/ethylation agent/process is distinguished by its environmental compatibility and it is, for example, suitable for the production of initial products for the synthesis of biologically effective compounds.
The copper mediated Barbier reactions of α,β-unsaturated ketones: Regioselective conjugate and 1,2-addition
Costello, Declan P.,Geraghty, Niall W. A.
, p. 3083 - 3096 (2007/10/03)
The one-pot reaction of isophorone and other α,β-unsaturated ketones with alkyl and aryl halides in the presence of magnesium and a copper salt ('Barbier' conditions) leads to the regiospecific formation of 1,4-addition products; the use of lithium leads to regioselective 1,2-addition.
