Weedon studies

Faraday, in 1834, was the first to encounter Kolbe-electrolysis, when he studied the electrolysis of an aqueous acetate solution [1], However, it was Kolbe, in 1849, who recognized the reaction and applied it to the synthesis of a number of hydrocarbons [2]. Thereby the name of the reaction originated. Later on Wurtz demonstrated that unsymmetrical coupling products could be prepared by coelectrolysis of two different alkanoates [3]. Difficulties in the coupling of dicarboxylic acids were overcome by Crum-Brown and Walker, when they electrolysed the half esters of the diacids instead [4]. This way a simple route to useful long chain l,n-dicarboxylic acids was developed. In some cases the Kolbe dimerization failed and alkenes, alcohols or esters became the main products. The formation of alcohols by anodic oxidation of carboxylates in water was called the Hofer-Moest reaction [5]. Further applications and limitations were afterwards foimd by Fichter [6]. Weedon extensively applied the Kolbe reaction to the synthesis of rare fatty acids and similar natural products [7]. Later on key features of the mechanism were worked out by Eberson [8] and Utley [9] from the point of view of organic chemists and by Conway [10] from the point of view of a physical chemist. In Germany [11], Russia [12], and Japan [13] Kolbe electrolysis of adipic halfesters has been scaled up to a technical process. 

Weedon BC, Some recent studies on carotenoids and related compounds. Pure... 

R.K. Sahoo, D.M. Weedon, D. Roach, Coal degradation, Part-2 experimental study of several factors affecting Gladstone Port Authority s lump coal degradation, BSH 22 (5) (2002) 356-361. 

Migrations are considerably more uncommon. Skinner and Weedon have studied the photochemical deconjugation reaction of a, -unsaturated esters... 

The addition of alkyl radicals to less reactive alkenes becomes more efficient if the addition is conducted intramolecularly. The Kolbe electrolysis of A 7- and A -unsaturated carboxylates produces five-and six-membered rings in a 5- or 6-cj o-rng-cyclization. ° Such a cyclization was first observed by Weedon and later studied in more detail." By intramolecular addition of appropriate precursors, 3-substituted tetrahydrofurans (Scheme 10 40, 41%), pyrrolidines (41, 53%), and cyclopentanes (42, 74%), and (43, 75%) are obtained. In the reactions leading to cyclopentanes the extent of cyclization... 

Weedon has reviewed the photochemical reactions in which enols are formed or used in synthesis. This particular reaction mode has been a successful photochemical route to many compounds over the years. Some publications relevant to this have appeared in the past year such as the study of the photochemical addition of... 

Ber. 67, 339. 1133 (1934) from the flowers of Tagetes patula L., Composita Found also in other Rosa varieties.. Structural studies Brown, Weedon, Chem. Commun. 1968, 382. Abs config L. Bartlett et ai. J. Chem. Soc. (C) 1969, 2327. Biosynthesis studies McDermott et ai. Biochem. J. 134, 1115 (1973). Has no vitamin A activity. 

Hastings DJ, Weedon AC (1991) Stereochemical studies of the photochemical cycloaddition reaction of alkenes with N-henzoylindole and N-carboethoxyindole evidence for biradical intermediacy. Can J Chem 69 1171-1181... 

Total chemical synthesis of a carotenoid is also an important step in structural and stereochemical studies (Section III,D). The total synthesis of vitamin A was first reported by Isler et al. (1947), and in 1950 the synthesis of )8-carotene was described by three groups (Karrer and Eugster, 1950 Inhof-fen et al., 1950a,b,c Milas et al., 1950). Since then, a large number of natural carotenoids and related compounds have been synthesized. Some of the historical aspects of this work were discussed recently by Weedon (1979) and Isler (1979). Chemical synthesis of carotenoids was also the subject of an extensive review by Mayer and Isler (1971). More recently, several additional aspects of the chemical synthesis of carotenoids have been discussed by Bestmann (1979) and Mayer (1979). 

Gallagher RP, Bajdik CD, Fincham S, Hill GB, Keefe AR, Goldman A, McLean DI (1996) Chemical exposures, medical history, and risk of squamous and basal cell carcinoma of the skin. Cancer Epidemiol Biomarkers Prev 5 419-424 Green A, Battistutta D, Hart V, Leslie D, Weedon D, Nambour Study Group (1996) Skin cancer in a subtropical Australian... 

Ansell and Weedon have presented further reports on their studies of the alkali fusion of unsaturated acids, and of 0x0-, hydroxy-, epoxy-, and alkoxy-acids. The fission of 9(10)-hydroxy-10(9)-oxo-octadecanoic acid by alcoholic alkali at room temperature has been confirmed and shown to be an autoxida-tion reaction. ... 

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