Acid Rearrangement Research Articles

The rearrangement of phenylsulphamic acid to sulphanilic acid in the presence of [35S]sulphuric acid

The rearrangement of phenylsulphamic acid to sulphanilic acid, which has often been cited as being intramolecular in character, is shown to proceed, at least in dioxan–sulphuric acid, by an intermolecular path. In this medium the rearrangement is demonstrated to involve a rapid hydrolysis of the phenylsulphamate species followed by a slow sulphonation reaction.

The rearrangement of orthanilic acid to sulphanic acid in the presence of sulphuric acid-s 35

The conversion of orthanilic acid to sulphanilic acid has been studied in the presence of radio-labelled sulphuric acid-S 35. The rearrangement involved is irreversible and is shown to proceed in conc H 2SO 4 by an intermolecular mechanism, in common with similar rearrangements of the toluenesulphonic acids and the chlorobenzenesulphonic acids. The sulphonic acids involved in the present study exchange without isomerization to a limited extent under rearrangement conditions. Several reasons for this exchange are advanced and discussed.

Structure and stereochemistry of the benzilic acid rearrangement product of 3.alpha.,17.beta.-diacetoxy-11-hydroxy-5.beta.-androst-9-(11)en-12-one

Structure and stereochemistry of the benzilic acid rearrangement product of 3.alpha.,17.beta.-diacetoxy-11-hydroxy-5.beta.-androst-9-(11)en-12-one

The carotenoids of blue-green algae—III. : A comparative study of mutatochrome and flavacin

Flavacin, obtained in small quantity from Aphanizomenon flos-aquae and Oscillatoria agardhii has been directly compared with mutatochrome (III), synthesized by monoperphthalic acid oxidation of β-carotene (I) to β-carotene-monoepoxide (II) and subsequent acid rearrangement. The results favour identity, although the available evidence does not rule out stereochemical differences. Complex metal hydride reduction of mutatochrome (III) (and flavacin) resulted in hydrogenolytic opening of the oxide ring. The main product 5-hydroxy-5,6-dihydro-β-carotene (IV) was dehydrated by phosphorous oxychloride to α-carotene (V).

The molecular structure of the benzilic acid rearrangement product of 3α, 17β-diacetoxy-11-hydroxy-12-oxo-5β-androst-9(11)-ene

Die Struktur desp-Brombenzoates des Benzilsaureumlagerungsproduktes von 3α, 17β-Diacetoxy-11-hydroxy-12-oxo-5β-Δ9(11)-androsten wurde durch dreidimensionale Rontgenstrukturanalyse eines Einkristalls als 3-p-Brombenzoat des 11β-Carboxy-3α, 11α, 17β-trihydroxy-13α-C-nor-5β-androstan 11a, 17-Laktons erkannt.

The chemistry of hydroxyquinones. Part I. The reaction of 2-hydroxybenzoquinones with alkaline hydrogen peroxide

The reaction of 2-hydroxybenzoquinones with alkaline hydrogen peroxide involves initial formation of the 5,6-diol. Quinones having no 6-substituent give a product which is subject to rapid oxidation by molecular oxygen to yield an α,β,γ-triketone which suffers a benzylic acid rearrangement at the 6,1-diketo-group and subsequent decarboxylation to form a 4,5-dihydroxycyclopentane-1,3-dione. Under acid conditions the latter is rapidly dehydrated to a cyclopentane-1,2,4-trione containing one less carbon atom than the original quinone.Quinones containing a 6-methyl group undergo an α-ketol rearrangement at the 6,1-α-ketol group to give a 4-acetyl-4,5-dihydroxycyclopenta-1,3-dione which is stable under alkaline conditions. In acid these products suffer deacetylation and dehydration to give cyclopentane-1,2,4-triones containing two carbon atoms less than the original quinone.

Norsteroids. V. The Application of the Benzilic Acid Rearrangement to the Synthesis of A-Norpregnanes1,2

Norsteroids. V. The Application of the Benzilic Acid Rearrangement to the Synthesis of A-Norpregnanes^1,2

321. The nitrous acid rearrangement of a 4-cyano-4,5-dihydroazepine

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3-Deoxyglycosuloses (3-Deoxyglycosones) and the Degradation of Carbohydrates

This chapter discusses the 3-deoxyglycosuloses as intermediates in the formation of metasaccharinic acids by the action of alkali on reducing sugars. The part played by 3-deoxyglycosuloses and their enolic forms, and by unsaturated glycosuloses, in the degradation of carbohydrates dealt, particularly with respect to the formation of 2-furaldehydes. 3-Deoxyglycosuloses are included in the review on dicarbonyl carbohydrates. 3-Deoxy-D-erythro-hexosulose is obtained as a colorless, hygroscopic powder of empirical formula C6H10O5. The compound is soluble in water, methanol, and ethanol, but insoluble in dry acetone, ethyl acetate, and ether. Osazones are readily formed from 3-deoxy-Derythro-hexosulose in the presence or absence of acid. The reactions proceed more rapidly with calcium hydroxide than with sodium hydroxide, and the stereospecificity of the benzilic acid rearrangement appears to be influenced by cationic catalysis, more of the arabino epimer being formed with sodium hydroxide.

An α-diketone from the condensation product of glucose and ethyl acetoacetate

When the product from the condensation of glucose and ethyl acetoacetate, ethyl 2-D-arabino-tetrahydroxybutyl-5-methyl-4-furoate (Ia), is heated in ethanolic hydrogen chloride, an a-diketone (IVa) is produced. It exists as a mono-enol in solution and in the solid state. Although this diketone is formed with an aliphatic side chain, there is at first a predominant, but reversible, cyclization to the "difuran" (II). With hydrogen peroxide the diketone yields 2-carboxymethy1-5- methyl-4-furoic acid (VII), and with alkali it undergoes a benzilic acid rearrangement.

Eine neue gerüstumlagerung des erythrinanrings

The acid rearrangement of cis-dimethoxy-6(α)-hydroxy-erythrinan-8-on II to the isomeric hydroxy-lactam VIII is described. The new compound has the character of weak base, which is able to form yellow salts of the cation VII.

The transformation of d-homosteroids to steroids : A stereospecific benzilic acid rearrangement

The d-homoannulation of some cortical hormones has been effected with a view toward transforming the products so obtained to d-homo-17,17a-diones. The latter, conveniently prepared by this means, were studied in the benzilic acid rearrangement mode of ring contraction back to steroids bearing a 17β-carboxyl and a 17β-hydroxyl. This rearrangement has been found to proceed in one steric sense, which may be accounted for on the basis of intermediates generated in compliance with the principles of conformational analysis.

The Catalytic Activity of Thiourea and Thiourea Analogues in the Rearrangement of Maleic Acid to Fumaric Acid

Angewandte Chemie International Edition in EnglishVolume 1, Issue 6 p. 330-330 Communication The Catalytic Activity of Thiourea and Thiourea Analogues in the Rearrangement of Maleic Acid to Fumaric Acid Dr. W. Schliesser, Dr. W. Schliesser Badische Anilin- & Soda-Fabrik, Ludwigshafen/Rh. (Germany) Search for more papers by this author Dr. W. Schliesser, Dr. W. Schliesser Badische Anilin- & Soda-Fabrik, Ludwigshafen/Rh. (Germany) Search for more papers by this author First published: June 1962 https://doi.org/10.1002/anie.196203301Citations: 4 Dedicated to Prof. Dr. G. Wittig on his 65th birthday. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume1, Issue6June 1962Pages 330-330 RelatedInformation

466. Mechanism of benzidine and semidine rearrangements. Part VI. Transitional kinetics and solvent-isotope effect in acid rearrangement of N-2-naphthyl-N′-phenylhydrazine

466. Mechanism of benzidine and semidine rearrangements. Part VI. Transitional kinetics and solvent-isotope effect in acid rearrangement of N-2-naphthyl-N′-phenylhydrazine

467. Mechanism of benzidine and semidine rearrangements. Part VII. Transitional kinetics and solvent-isotope effect in acid rearrangement of o-hydrazotoluene

467. Mechanism of benzidine and semidine rearrangements. Part VII. Transitional kinetics and solvent-isotope effect in acid rearrangement of o-hydrazotoluene

653. Mechanism of benzidine and semidine rearrangements. Part IX. Substrate-isotope effects on kinetics and products of acid rearrangement of 1,1′-hydrazonaphthalene

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463. Mechanism of benzidine and semidine rearrangements. Part III. Kinetics and products of acid rearrangement of 2,2′-hydrazonaphthalene

463. Mechanism of benzidine and semidine rearrangements. Part III. Kinetics and products of acid rearrangement of 2,2′-hydrazonaphthalene

654. Mechanism of benzidine and semidine rearrangements. Part X. Substrate-isotope effects on kinetics and products of acid rearrangement of the hydrazobenzenes

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462. Mechanism of benzidine and semidine rearrangements. Part II. Kinetics and products of acid rearrangement of 1,2′-hydrazonaphthalene

462. Mechanism of benzidine and semidine rearrangements. Part II. Kinetics and products of acid rearrangement of 1,2′-hydrazonaphthalene

465. Mechanism of benzidine and semidine rearrangements. Part V. Transitional kinetics and products of acid rearrangement of N-1-naphthyl-N′-phenylhydrazine

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