The mechanism of lead tetraacetate decarboxylation. I. Tertiary carboxylic acids

1974 ◽  
Vol 27 (8) ◽  
pp. 1673 ◽  
Author(s):  
ALJ Beckwith ◽  
RT Cross ◽  
GE Gream
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Carboxylic Acid ◽  
Product Distribution ◽  
Lead Tetraacetate ◽  
Copper Salts ◽  
Elimination Process ◽  
Initial Generation ◽  
Cis And Trans ◽  
Lead Species

The reactions of cis- and trans-decalin-9-carboxylic acid, 2,2,3-trimethylbutanoic acid, and adamantane-1-carboxylic acid with lead tetraacetate in benzene and, in some cases, acetic acid have been studied. In each case the nature and distribution of the products is consistent with the hypothesis that the reaction mechanism involves the initial generation of tertiary radicals which are subsequently converted into the related cations either by one-electron oxidation by lead species, or via organolead intermediates which undergo heterolysis. The change in product distribution which occurs when the reactions are conducted in the presence of copper salts indicates that tertiary radicals react rapidly with cupric species to afford organocopper intermediates from which olefins are derived by a cis-elimination process, and acetates by SNi or heterolytic mechanisms.

Improved synthesis of anti-sesquinorbornene

1984 ◽  
Vol 62 (9) ◽  
pp. 1840-1844 ◽  
Author(s):  
Karl R. Kopecky ◽  
Alan J. Miller
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Lead Tetraacetate ◽  
Carboxyl Group ◽  
Silver Acetate ◽  
Benzenesulfonyl Chloride ◽  
Methoxide Ion ◽  
Hydrolysis Of ◽  
Monomethyl Ester

Treatment of methyl hydrogen decahydro-1,4:5,8-exo,endo-dimethanonaphthalene-4a,8a-dicarboxylate with lead tetraacetate in benzene – acetic acid replaces the carboxyl group by an acetoxy group. Hydrolysis of this product with 25% sulfuric acid at 130 °C forms 8a-hydroxydecahydro-1,4:5,8-exo,endo-dimethanonaphthalene-4a-carboxylic acid 10. The reaction between 10 and benzenesulfonyl chloride in pyridine containing triethylamine at 95 °C produces anti-sesquinorbornene 1 in 34% yield. In the absence of triethylamine 1 is converted to the hydrochloride. The iodohydroperoxide of 1 is converted by silver acetate at 0 °C to the diketone in a luminescent reaction. The 1,2-dioxetane could not be isolated. Decahydro-1,4:5,8-exo,exo-dimethanonaphthalene-4a,8a-dicarboxylic anhydride is converted slowly by methoxide ion in methanol at 150 °C to the monomethyl ester which then undergoes demethylation. The isomeric exo,endo anhydride undergoes reaction readily with methoxide ion at 80 °C.

The camphenehydro (methylcamphenilyl) and isobornyl (bornyl) cations. III. Oxidative decarboxylation of carboxylic acids with lead tetraacetate

1974 ◽  
Vol 27 (3) ◽  
pp. 603 ◽  
Author(s):  
GE Gream ◽  
CF Pincombe ◽  
D Wege
Keyword(s):  
Carboxylic Acid ◽  
Marked Change ◽  
Lead Tetraacetate ◽  
Dimethyl Sulphoxide ◽  
Oxidative Decarboxylation ◽  
Propanoic Acid ◽  
Acid Yield ◽  
Cupric Acetate ◽  
Initial Generation ◽  
Almost All

The oxidative decarboxylation of exo- and endo-bornane-2-carboxylic acid, exo- and endo-2,3,3- trimethylnorbornane-2-carboxylic acid and a-campholenylcarboxylic acid [3-(2',2',3'-trimethyl- cyclopent-3'-eny1)propanoic acid] with lead tetraacetate in benzene and dimethyl sulphoxide (each containing pyridine) in the presence, and absence, of cupric acetate has been investigated. The mode of formation of almost all the products can be satisfactorily rationalized in terms of the initial generation of radicals. In the case of exo- and endo-bornane-2-carboxylic acid, the derived bornyl radical forms organolead and organocopper derivatives that decompose in three ways: (1) by heterolysis by the direct route to give the equilibrating isobornyl and camphenehydro cations, (2) by a cyclic cis-elimination to give bornylene and (3) by an SNi process to give isobornyl and bornyl acetates. exo- and endo-2,3,3-Trimethylnorbornane-2-carboxylic acid yield the 2,3,3-trimethyl- norborn-2-yl radical which is converted into the equilibrating camphenehydro and isobornyl cations either by one-electron oxidation by lead species or via organolead or organocopper derivatives which undergo heterolysis. Processes involving cyclic cis-elimination and SNi substitution may also operate in the organometallic derivatives derived from the tertiary radical. a-Campholenylcarboxylic acid yields the a-campholenyl radical which, in the absence of cupric acetate, undergoes in the main cyclization to give the 2,3,3-trimethylnorbornyl radical. The resulting mixture of products is similar to that obtained from exo- and endo-2,3,3-trimethylnorbornane-2- carboxylic acid. In the presence of cupric acetate, the a-campholenyl radical is trapped at least to the extent of 50% in benzene and 80% in dimethyl sulphoxide to give the corresponding organo- copper derivative which undergoes a cyclic elimination to give 2,3,3-trimethyl-4-vinylcyclopentene and may undergo heterolysis by the x-route to give the camphenehydro and isobornyl cations. A marked change in the composition of the products on changing the solvent from benzene to dimethyl sulphoxide is observed only in the case of a-campholenylcarboxylic acid in the presence of cupric acetate.

Reactions of lead tetraacetate. I. Formation of acylamines from primary carboxamides

1968 ◽  
Vol 21 (1) ◽  
pp. 185 ◽  
Author(s):  
B Acott ◽  
ALJ Beckwith ◽  
A Hassanali
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Benzoic Acid ◽  
Intermediate Formation ◽  
Lead Tetraacetate ◽  
Acid Mixture ◽  
Curtius Rearrangement ◽  
Alkyl Isocyanate

Pentanamide, when treated with lead tetraacetate in hot benzene, affords a mixture of N-butylacetamide and N,N?-dibutylurea. Examples of similar transformations of a number of primary carboxamides are described. The reaction, which may also be conducted in acetic acid or benzene-acetic acid mixture, is catalysed by pyridine. Cyclohexanecarboxamide, when oxidized by lead tetraacetate in the presence of propionic or benzoic acid, is converted into the appropriate acylcyclohexylamine. The reaction mechanism involves intermediate formation of alkyl isocyanate, possibly via Curtius rearrangement of acylnitrene.

The mechanism of lead tetraacetate decarboxylation. II. 2,3,3-Trimethylbutanoic and Adamantane-2-carboxylic acids

1974 ◽  
Vol 27 (8) ◽  
pp. 1693 ◽  
Author(s):  
ALJ Beckwith ◽  
RT Cross ◽  
GE Gream
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Major Product ◽  
Lead Tetraacetate ◽  
Oxidative Decarboxylation ◽  
Catalysed Reaction

Oxidative decarboxylation of 2,3,3-trimethylbutanoic acid with lead tetraacetate in benzene or acetic acid affords mainly 3,3-dimethylbut-2-yl acetate; the major product from the cupric salt catalysed reaction is 3,3-dimethylbut-1-ene. The low yields detected of rearrangement products provide evidence for the intermediacy of organolead and organocopper compounds which decompose by SNi displacement or cyclic cis-elimination. Other reactions discussed are oxidative decarboxylation of adamantane-2-carboxylic acid, deamination of 3,3-dimethylbut-2-ylamine, and thermolysis of bis(2,3,3-trimethylbutanoyl) peroxide and of t-butyl adamantane-2-percarboxylate. A reinterpretation of previous results on the oxidative decarboxylation of exo- and endo-nor- bornane-2-carboxylic acid with lead tetraacetate is presented.

Theoretical study of the ketonization reaction mechanism of acetic acid over SiO2

2009 ◽  
Author(s):  
Mendel Fleisher ◽  
E. Lukevics ◽  
L. Leite ◽  
D. Jansone ◽  
K. Edolfa ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Theoretical Study

The synthesis of norbornanes with functionalized carbon substituents at a bridgehead. 1-(3-Oxonorborn-1-yl)ethanone and 1-(3-oxonorborn-1-yl)-2-propanone

1992 ◽  
Vol 70 (5) ◽  
pp. 1492-1505 ◽  
Author(s):  
Peter Yates ◽  
Magdy Kaldas
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Hydrogen Bromide ◽  
Tertiary Alcohol ◽  
Ethyl Bromoacetate ◽  
Second Molar ◽  
Molar Equivalent ◽  
Acid Lactone ◽  
Basic Hydrolysis ◽  
Hydrolysis Of

Treatment of 2-norobornene-1-carboxylic acid (7) with one equivalent of methyllithium in ether followed by a second molar equivalent after dilution with tetrahydrofuran gave 1-(norborn-2-en-lyl)ethanone (10) and only a trace of the tertiary alcohol 11. Reaction of 7 with formic acid followed by hydrolysis gave a 4:3 mixture of exo-3- and exo-2-hydroxynorbornane-1-carboxylic acid (16 and 17), whereas oxymercuration–demercuration gave only the exo-3-hydroxy isomer 16. Oxidation of 16 and 17 gave 3- and 2-oxonorbornane-1-carboxylic acid (27 and 29), respectively. Oxymercuration–demercuration of 10 gave exclusively 1-(exo-3-hydroxynorborn-1-yl)ethanone (30), which was also prepared by treatment of 16 with methyllithium in analogous fashion to that used for the conversion of 7 to 10. Oxidation of 30 gave 1-(3-oxonorborn-1-yl)ethanone (1). Dehydrobromination of exo-2-bromonorbornane-1-acetic acid and dehydration of 2-hydroxy-norbornane-2-acetic acid derivatives gave 1-(norborn-2-ylidene) acetic acid derivatives to the exclusion of norborn-2-ene-1 -acetic acid derivatives. Treatment of exo-5-acetyloxy-2-norobornanone (52) with ethyl bromoacetate and zinc gave ethyl exo-5-acetyloxy-2-hydroxynorbornane-(exo- and endo-2-acetate (53 and 54). Reaction of 53 with hydrogen bromide gave initially ethyl endo-3-acetyloxy-exo-6-bromonorbornane-1-acetate (59), which was subsequently converted to a mixture of 59 and its exo-3-acetyloxy epimer 61. Catalytic hydrogenation of this mixture gave a mixture of ethyl endo- and exo-3-acetyloxynorbornane-1 -acetate (62 and 63). Basic hydrolysis of this gave a mixture of the corresponding hydroxy acids, 70 and 71; the former was slowly converted to the latter at pH 5. Oxidation of the mixture of 70 and 71 gave 3-oxonorbornane-1-acetic acid (72). Treatment of the mixture with methyllithium as for 16 gave a mixture of 1-(endo- and exo-3-hydroxynorborn-1-yl)-2-propanone (73 and 74), which was oxidized to 1-(3-oxo-norborn-1-yl)-2-propanone (2). Reaction of exo-2-hydroxynorbornane-1-acetic acid lactone (75) with methyllithium in ether gave (1-(exo-2-hydroxynorborn-1-yl)-2-propanone (76), which on oxidation gave the 2-oxo isomer 78 of 2.

Lead Tetraacetate Oxidations in the Sugar Group. V.1The Rates of Oxidation of Open-Chain Polyalcohols in Dry Acetic Acid Solution2

1944 ◽  
Vol 66 (3) ◽  
pp. 467-468 ◽  
Author(s):  
Robert C. Hockett ◽  
Margaret T. Dienes ◽  
Hewitt G. Fletcher ◽  
Hugh E. Ramsden
Keyword(s):  
Acetic Acid ◽  
Lead Tetraacetate ◽  
Open Chain ◽  
Group V

scholarly journals Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
The Other ◽  
Other Hand ◽  
Three Component Reaction ◽  
High Yields

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.

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