Showing papers in "Journal of Chemical Research-s in 1990"

Improved procedure for the cleavage of alkyl and benzyl ethers with zinc iodide

Abstract: Zinc iodide in the presence of acylating agents such as carboxylic acid anhydrides and chlorides cleaves alkyl and benzyl ethers efficiently under mild conditions

A Convenient One-pot Preparation of Te-Alkyl Tellurocarboxylates via the Successive Acylation and Alkylation of Telluride Anion. Application to the Synthesis of Alkyl Telluroimidates

Abstract: La synthese s'effectue a partir du chlorure de benzoyle ou de l'N-(α-alkyltellurobenzylidene) p-toluenesulfonamide, et de l'hydrogenotellurure de sodium

Intramolecular hydrogen abstraction. (Diacetoxyiodo)benzene, a useful reagent for the remote functionalization of non-activated carbon atoms

Abstract: 2 pages, 1 scheme.-- Paper in Journal of Chemical Research(M) available at: http://hdl.handle.net/10261/16430

Salt effects on the protonation of ethylenediamine : a complex-formation model

Abstract: We report a potentiometric investigation (glass electrode) on the protonation of ethylenediamine in LiCl, NaCl, KCl, NaNO 3 , NaClO 4 , MgCl 2 , CaCl 2 , Me 4 NCl, and Et 4 NI (Me 4 N + and Et 4 N + are tetramethylammonium and tetraethylammonium cations respectively) at T=25 o C. The literature on the protonation of ethylenediamine 11 was also examined

A novel reductive desulphonation of acyl sulphones

Abstract: Sodium dithionite is shown to be a useful reagent for the reductive desulphonation of acyl sulphones under mild conditions which should be readily applicable to large scale synthesis

Synthetic methods for benzo-crown ethers

Abstract: La meilleure methode est celle ou l'on fait reagir le bis-[hydroxy-2p ethoxy]-1,2 benzene avec le ditosylate de l'oligoethylene glycol, en presence d'hydrure de sodium, dans le THF

A convenient method for the synthesis of diaroyl diselenides from selenium under phase-transfer conditions

Abstract: A simple and general method for the synthesis of diaroyl diselenides involves reaction of selenium with sodium hydroxide at 65-70 o C and under phase-transfer conditions to give sodium diselenide, which reacts with aroyl chlorides to afford the diaroyl diselenides in good to excellent isolated yields

Hydrogen-bond basicity of cyanamide, amide, thioamide, and sulphonamide iminologues

Abstract: Compounds Me 2 N―CH=N―A are considered as iminologues of compounds Me 2 N―A and it is shown that iminology extends significantly the range of hydrogen-bond basicities of nitriles, thioamides, and sulphonamides

Isolation and characterization of luteolin 6-O-β-D-glucopyranoside 3'-O-α-L-rhamnoside from Ficus infectoria

Abstract: A novel flavone glycoside, designated as infectoriin, has been isolated from the leaves of Ficus infectoria (Moraceae) and has been assigned the structure 1 on the basis of chemical and spectral evidence

Syntheses of thyroliberin analogues in which the C-terminal amide and the τ-position of the histidine side-chain are bridged. Regiospecific τ-im-alkylation and 2-hydroxyphenyl ester cyclopeptide synthesis exemplified

Abstract: Syntheses of the bridged thyroliberin analogues pyroglutamyl-cyclo-Nτ-(6-aminohexyl) histidylproline (1a) and pyroglutamyl-cyclo-Nτ-(5-aminopentyl) histidylproline (1b) are described, exemplifying a novel method of regiospecific τ-im-alkylation and also cyclopeptide synthesis via 2-hydroxyphenyl esters