A new route to exomethylene sugars is reported. The use of a two-step coupling-elimination procedure allows successful Julia olefination of sugar-derived lactones.
Carbohydrates U 0500 Synthesis of Methylene Exoglycals Using a Modified Julia Olefination. -A new approach to exomethylene sugars is developed. They are of synthetic and biological interest. -(GUEYRARD*, D.; HADDOUB, R.; SALEM, A.; BACAR, N. S.; GOEKJIAN, P. G.; Synlett 2005, 3, 520-522; Lab. Chim. Org., CNRS, Univ. Claude Bernard Lyon, F-69622 Villeurbanne, Fr.; Eng.) -Jannicke 29-199
Acetylation of anthracene by the Friedel-Crafts Reaction using ethylene chloride as the solvent leads to a high yield of 1-acetylanthracene. Diacetylation gives a mixture of 1,s-and 1,s-diacetylanthtacene. Oxidation to the corresponding acetylanthraquinones and carboxylic acids is described.
IntroductionThe authors i n a previous publication 1 described the acetylation of anthracene using chloroform as the solvent. This, publication deals with the reaction in another solvent, ethylene chloride, which, although resembling chloroform in many respects, showed a different orienting effect.
Nitration of I-chloronaphthalene with excess of fuming nitric acid at a relatively high temperature provided a mixture of I-chloro-4,s-and l-chloro-4,8-dinitronaphthalenes. The same dinitro derivatives can be obtained by further nitration of 1-chloro-4-nitronaphthalene. The nitration of l-chloro-4,5-dinitronaphthalene with eithcr fuming nitric acid or mixed acids provides the known I-chloro-2,4,S-trinitronaphthalene, while that of l-chloro-4,8-dinitronaphthalene with fuming nitric acid yields a new trinitro derivative melting with decomposition at 270 which is confirmed as being 1 -chloro-4,5,8-trinitronaphthalene.
IntroductionThe dinitro derivatives of 1 -chloronaphthalene described in the literature are those having the nitro groups in the 4,8-, 4,5-and 2,4-pmitions; only the first two derivatives can be prepared by direct nitration of l-chloronaphthalene. The present authors during a previous investigation 1 found that the direct nitration of 1 mole of 1-chloronaphthalene with up to 8 moles of fuming nitric acid at 5 O provided a mixture of l-chloro-4-nitronaphthalene, m.p. 85 O and l-chloro-4,5-dinitronaphthalene, m.p. 180 O. Atterberg 2 using excess fuming nitric acid, but giving no experimental details, carried out the nitration of 1-chloronaphthalene and obtained two dinitro derivatives, m.p. 106 and 180 O which were shown to be l-chloro-4,8-dinitro-and l-chloro-4.5-dinitronaphthalene, respectively.
1-and 2-Methylnaphthalene react with maleic anhydride in ethylene chloride and in absence of excess of aluminium chloride to. give methylnaphthoylacrylic acids which are cyclised in molten aluminium chloridesodium chloride a t 100-120" by addition of the double bond to the naphthalene nucleus. The structure of the cyclised acids was established, and an easy and reliable method for oxidation of naphthalene derivatives to the csrboxylic acids is described.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.