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Janice M. Nelke - One of the best experts on this subject based on the ideXlab platform.
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the Acyloin condensation
Organic Reactions, 2011Co-Authors: Jordan J. Bloomfield, Dennis C. Owsley, Janice M. NelkeAbstract:The Acyloin condensation usually involves the reductive dimerization of a carboxylic ester, although acid chlorides and the anhydrides have been used. The reducing agent is in an alkali metal and the product is an ene-diolate. Two gram-atoms of metal are required for each mole of ester with the concomitant formation of a mole of akoxide and one-half mole of the ene-diolate. Oxidation of Acyloins to diketoes can be accomplished by a variety of reagents. Acyloins can be reduced to ketones by various modifications of the Clemmenson technique. Under mild conditions the ketone will dominate. This chapter presents a complete picture of both the linear and cyclic Acyloin condensation with particular emphasis on developments since 1960. The discussion is closely limited to the Acyloin condensation and its modifications. Keywords: condensation; Acyloin; dicarboxylic acids; monocarboxyl acids; reduction; oxalates; malonates; succinates; glutarates; adipates; pimelates; heterocyclic esters; esters; ketone; semidiones; experimental procedures
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Organic Reactions - The Acyloin Condensation
Organic Reactions, 2011Co-Authors: Jordan J. Bloomfield, Dennis C. Owsley, Janice M. NelkeAbstract:The Acyloin condensation usually involves the reductive dimerization of a carboxylic ester, although acid chlorides and the anhydrides have been used. The reducing agent is in an alkali metal and the product is an ene-diolate. Two gram-atoms of metal are required for each mole of ester with the concomitant formation of a mole of akoxide and one-half mole of the ene-diolate. Oxidation of Acyloins to diketoes can be accomplished by a variety of reagents. Acyloins can be reduced to ketones by various modifications of the Clemmenson technique. Under mild conditions the ketone will dominate. This chapter presents a complete picture of both the linear and cyclic Acyloin condensation with particular emphasis on developments since 1960. The discussion is closely limited to the Acyloin condensation and its modifications. Keywords: condensation; Acyloin; dicarboxylic acids; monocarboxyl acids; reduction; oxalates; malonates; succinates; glutarates; adipates; pimelates; heterocyclic esters; esters; ketone; semidiones; experimental procedures
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Organic Syntheses - Acyloin Condensation in which Chlorotrimethylsilane is used as a Trapping Agent: 1,2‐Bis(trimethylsilyloxy)cyclobutene and 2‐Hydroxycyclobutanone
Organic Syntheses, 2003Co-Authors: Jordan J. Bloomfield, Janice M. NelkeAbstract:Acyloin condensation in which chlorotrimethylsilane is used as a trapping agent: 1,2-bis(trimethylsilyloxy)cyclobutene and 2-hydroxycyclobutanone product: 1,2-Bis(trimethylsilyloxy)cyclobutene product: 2-hydroxycyclobutanone Keywords: coupling; cyclization, reductive cyclization; reduction, miscellaneous; chlorotrimethylsilane, drying of; sodium sand; sodium-potassium alloy; toluene; chlorotrimethylsilane, in Acyloin reactions; sodium-potassium alloy; addition funnels, Hershberg; dry-box, in the preparation of 2-hydroxycyclobutanone; stirrers, vibromixer; vibromixer
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Acyloin condensation in which chlorotrimethylsilane is used as a trapping agent 1 2 bis trimethylsilyloxy cyclobutene and 2 hydroxycyclobutanone
Organic Syntheses, 2003Co-Authors: Jordan J. Bloomfield, Janice M. NelkeAbstract:Acyloin condensation in which chlorotrimethylsilane is used as a trapping agent: 1,2-bis(trimethylsilyloxy)cyclobutene and 2-hydroxycyclobutanone product: 1,2-Bis(trimethylsilyloxy)cyclobutene product: 2-hydroxycyclobutanone Keywords: coupling; cyclization, reductive cyclization; reduction, miscellaneous; chlorotrimethylsilane, drying of; sodium sand; sodium-potassium alloy; toluene; chlorotrimethylsilane, in Acyloin reactions; sodium-potassium alloy; addition funnels, Hershberg; dry-box, in the preparation of 2-hydroxycyclobutanone; stirrers, vibromixer; vibromixer
Kunio Ogasawara - One of the best experts on this subject based on the ideXlab platform.
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Lipase-mediated kinetic resolution of tricyclic Acyloins, endo-3-hydroxytricyclo[4.2.1.02,5]non-7-en-4-one and endo-3-hydroxytricyclo[4.2.2.02,5]dec-7-en-4-one
Tetrahedron: Asymmetry, 1997Co-Authors: Takahiko Taniguchi, Regina Mikie Kanada, Kunio OgasawaraAbstract:Abstract Kinetic resolution of tricyclic Acyloins, endo -3-hydroxytricyclo[4.2.1.0 2,5 ]non-7-en-4-one and endo -3-hydroxytricyclo[4.2.2.0 2,5 ]dec-7-en-4-one, and their acetates has been examined using a lipase. It has been found that a facile and stereoselective kinetic resolution occurs both in organic solvent and an aqueous solution in enantiocomplementary ways to afford both enantiomers of the Acyloins and their acetates in enantiomerically pure forms. Enantiomerization of (+)-Acyloins leading to (−)-Acyloin acetates has also been achieved by the same lipase in an organic solvent by addition of a catalytic amount of triethylamine.
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Lipase–triethylamine-mediated dynamic transesterification ofa tricyclic Acyloin having a latent meso-structure: a new routeto optically pure oxodicyclopentadiene
Chemical Communications, 1997Co-Authors: Takahiko Taniguchi, Kunio OgasawaraAbstract:The racemic tricyclic Acyloin (±)-endo-3-hydroxytricyclo[4.2.1.0 2,5 ]non-7-en -4-one has been dynamically resolved via the transient formation of the meso-enediol isomer under lipase–triethylamine-mediated kinetic transesterification conditions to give the single chiral acetate (-)-endo-3-acetoxytricyclo[4.2.1.0 2,5 ]non-7-en- 4-one, serving as a precursor of (-)-oxodicyclopentadiene, in excellent optical and chemical yields.
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lipase triethylamine mediated dynamic transesterification ofa tricyclic Acyloin having a latent meso structure a new routeto optically pure oxodicyclopentadiene
Chemical Communications, 1997Co-Authors: Takahiko Taniguchi, Kunio OgasawaraAbstract:The racemic tricyclic Acyloin (±)-endo-3-hydroxytricyclo[4.2.1.0 2,5 ]non-7-en -4-one has been dynamically resolved via the transient formation of the meso-enediol isomer under lipase–triethylamine-mediated kinetic transesterification conditions to give the single chiral acetate (-)-endo-3-acetoxytricyclo[4.2.1.0 2,5 ]non-7-en- 4-one, serving as a precursor of (-)-oxodicyclopentadiene, in excellent optical and chemical yields.
Jordan J. Bloomfield - One of the best experts on this subject based on the ideXlab platform.
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the Acyloin condensation
Organic Reactions, 2011Co-Authors: Jordan J. Bloomfield, Dennis C. Owsley, Janice M. NelkeAbstract:The Acyloin condensation usually involves the reductive dimerization of a carboxylic ester, although acid chlorides and the anhydrides have been used. The reducing agent is in an alkali metal and the product is an ene-diolate. Two gram-atoms of metal are required for each mole of ester with the concomitant formation of a mole of akoxide and one-half mole of the ene-diolate. Oxidation of Acyloins to diketoes can be accomplished by a variety of reagents. Acyloins can be reduced to ketones by various modifications of the Clemmenson technique. Under mild conditions the ketone will dominate. This chapter presents a complete picture of both the linear and cyclic Acyloin condensation with particular emphasis on developments since 1960. The discussion is closely limited to the Acyloin condensation and its modifications. Keywords: condensation; Acyloin; dicarboxylic acids; monocarboxyl acids; reduction; oxalates; malonates; succinates; glutarates; adipates; pimelates; heterocyclic esters; esters; ketone; semidiones; experimental procedures
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Organic Reactions - The Acyloin Condensation
Organic Reactions, 2011Co-Authors: Jordan J. Bloomfield, Dennis C. Owsley, Janice M. NelkeAbstract:The Acyloin condensation usually involves the reductive dimerization of a carboxylic ester, although acid chlorides and the anhydrides have been used. The reducing agent is in an alkali metal and the product is an ene-diolate. Two gram-atoms of metal are required for each mole of ester with the concomitant formation of a mole of akoxide and one-half mole of the ene-diolate. Oxidation of Acyloins to diketoes can be accomplished by a variety of reagents. Acyloins can be reduced to ketones by various modifications of the Clemmenson technique. Under mild conditions the ketone will dominate. This chapter presents a complete picture of both the linear and cyclic Acyloin condensation with particular emphasis on developments since 1960. The discussion is closely limited to the Acyloin condensation and its modifications. Keywords: condensation; Acyloin; dicarboxylic acids; monocarboxyl acids; reduction; oxalates; malonates; succinates; glutarates; adipates; pimelates; heterocyclic esters; esters; ketone; semidiones; experimental procedures
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Organic Syntheses - Acyloin Condensation in which Chlorotrimethylsilane is used as a Trapping Agent: 1,2‐Bis(trimethylsilyloxy)cyclobutene and 2‐Hydroxycyclobutanone
Organic Syntheses, 2003Co-Authors: Jordan J. Bloomfield, Janice M. NelkeAbstract:Acyloin condensation in which chlorotrimethylsilane is used as a trapping agent: 1,2-bis(trimethylsilyloxy)cyclobutene and 2-hydroxycyclobutanone product: 1,2-Bis(trimethylsilyloxy)cyclobutene product: 2-hydroxycyclobutanone Keywords: coupling; cyclization, reductive cyclization; reduction, miscellaneous; chlorotrimethylsilane, drying of; sodium sand; sodium-potassium alloy; toluene; chlorotrimethylsilane, in Acyloin reactions; sodium-potassium alloy; addition funnels, Hershberg; dry-box, in the preparation of 2-hydroxycyclobutanone; stirrers, vibromixer; vibromixer
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Acyloin condensation in which chlorotrimethylsilane is used as a trapping agent 1 2 bis trimethylsilyloxy cyclobutene and 2 hydroxycyclobutanone
Organic Syntheses, 2003Co-Authors: Jordan J. Bloomfield, Janice M. NelkeAbstract:Acyloin condensation in which chlorotrimethylsilane is used as a trapping agent: 1,2-bis(trimethylsilyloxy)cyclobutene and 2-hydroxycyclobutanone product: 1,2-Bis(trimethylsilyloxy)cyclobutene product: 2-hydroxycyclobutanone Keywords: coupling; cyclization, reductive cyclization; reduction, miscellaneous; chlorotrimethylsilane, drying of; sodium sand; sodium-potassium alloy; toluene; chlorotrimethylsilane, in Acyloin reactions; sodium-potassium alloy; addition funnels, Hershberg; dry-box, in the preparation of 2-hydroxycyclobutanone; stirrers, vibromixer; vibromixer
H. Kuhlmann - One of the best experts on this subject based on the ideXlab platform.
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Organic Syntheses - Acyloin Condensation by Thiazolium Ion Catalysis: Butyroin
Organic Syntheses, 2003Co-Authors: H. Stetter, H. KuhlmannAbstract:Acyloin condensation by thiazolium ion catalysis: butyroin catalyst: 13.4 g (0.05 mol) of 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium chloride product: butyroin product: furoin Keywords: addition, to CO; acetonitrile; 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium chloride
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Acyloin condensation by thiazolium ion catalysis butyroin
Organic Syntheses, 2003Co-Authors: H. Stetter, H. KuhlmannAbstract:Acyloin condensation by thiazolium ion catalysis: butyroin catalyst: 13.4 g (0.05 mol) of 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium chloride product: butyroin product: furoin Keywords: addition, to CO; acetonitrile; 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium chloride
Takahiko Taniguchi - One of the best experts on this subject based on the ideXlab platform.
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Lipase-mediated kinetic resolution of tricyclic Acyloins, endo-3-hydroxytricyclo[4.2.1.02,5]non-7-en-4-one and endo-3-hydroxytricyclo[4.2.2.02,5]dec-7-en-4-one
Tetrahedron: Asymmetry, 1997Co-Authors: Takahiko Taniguchi, Regina Mikie Kanada, Kunio OgasawaraAbstract:Abstract Kinetic resolution of tricyclic Acyloins, endo -3-hydroxytricyclo[4.2.1.0 2,5 ]non-7-en-4-one and endo -3-hydroxytricyclo[4.2.2.0 2,5 ]dec-7-en-4-one, and their acetates has been examined using a lipase. It has been found that a facile and stereoselective kinetic resolution occurs both in organic solvent and an aqueous solution in enantiocomplementary ways to afford both enantiomers of the Acyloins and their acetates in enantiomerically pure forms. Enantiomerization of (+)-Acyloins leading to (−)-Acyloin acetates has also been achieved by the same lipase in an organic solvent by addition of a catalytic amount of triethylamine.
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Lipase–triethylamine-mediated dynamic transesterification ofa tricyclic Acyloin having a latent meso-structure: a new routeto optically pure oxodicyclopentadiene
Chemical Communications, 1997Co-Authors: Takahiko Taniguchi, Kunio OgasawaraAbstract:The racemic tricyclic Acyloin (±)-endo-3-hydroxytricyclo[4.2.1.0 2,5 ]non-7-en -4-one has been dynamically resolved via the transient formation of the meso-enediol isomer under lipase–triethylamine-mediated kinetic transesterification conditions to give the single chiral acetate (-)-endo-3-acetoxytricyclo[4.2.1.0 2,5 ]non-7-en- 4-one, serving as a precursor of (-)-oxodicyclopentadiene, in excellent optical and chemical yields.
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lipase triethylamine mediated dynamic transesterification ofa tricyclic Acyloin having a latent meso structure a new routeto optically pure oxodicyclopentadiene
Chemical Communications, 1997Co-Authors: Takahiko Taniguchi, Kunio OgasawaraAbstract:The racemic tricyclic Acyloin (±)-endo-3-hydroxytricyclo[4.2.1.0 2,5 ]non-7-en -4-one has been dynamically resolved via the transient formation of the meso-enediol isomer under lipase–triethylamine-mediated kinetic transesterification conditions to give the single chiral acetate (-)-endo-3-acetoxytricyclo[4.2.1.0 2,5 ]non-7-en- 4-one, serving as a precursor of (-)-oxodicyclopentadiene, in excellent optical and chemical yields.
