Synthesis of the Furan Derivatives. XXXV : Stereospecification of Wittig Reaction

comparison of catalytic activity of heteropoly compounds in the synthesis of bis(indolyl)alkanes.

heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...

α-Lithiated Aryl Benzyl Ethers: Inhibition of [1,2]-Wittig Rearrangement and Application to the Synthesis of Benzo[b]furan Derivatives.

The use of t-BuLi at low temperature selectively leads to α-lithiation of benzyl phenyl ether generating a stable organolithium, which can be efficiently trapped with a variety of selected electrophiles prior to suffering the expected [1,2]-Wittig rearrangement. In the case of (o-alkynyl)phenyl benzyl ethers, the intermediate α-aryloxyorganolithium undergoes an unexpected anti intramolecular ca...

Synthesis of Furan Derivatives Condensed with Carbohydrates

Eight new furan derivatives have been prepared and characterized. These compounds were obtained by condensation of aminosugar and aminocyclitol intermediates with furan derivatives.

The Wittig Reaction

The Wittig Reaction

This so-called Wittig reaction has a number of advantages over other olefination methods; in particular, it occurs with total positional selectivity (that is, an alkene always directly replaces a carbonyl group). By comparison, a number of other carbonyl olefination reactions often occur with double-bond rearrangement. In addition, the factors that influence Eand Z-stereoselectivity are well un...