Formation of β, γ-Unsaturated Carboxylic Acid Derivatives by the Wittig Reaction

Transformation of cholanic acid derivatives into pharmacologically active esters of phenolic acids by heterogeneous Wittig reaction.

Steroid esters of cynnamic acid derivatives have been synthesized by a heterogeneous Wittig reaction under sonochemical conditions from the corresponding triphenylphosphonium bromides and unprotected phenolic aldehyds using K2CO3 as a base. 5 beta-Cholan-3 alpha, 7 alpha, 12 alpha, 24-E-ferulate (11') exhibited a marked inhibitory effect on influenza virus A. The synthetic 3 alpha, 24-E-diferul...

Synthesis of α,β-unsaturated esters via a chemo-enzymatic chain elongation approach by combining carboxylic acid reduction and Wittig reaction

α,β-Unsaturated esters are versatile building blocks for organic synthesis and of significant importance for industrial applications. A great variety of synthetic methods have been developed, and quite a number of them use aldehydes as precursors. Herein we report a chemo-enzymatic chain elongation approach to access α,β-unsaturated esters by combining an enzymatic carboxylic acid reduction and...

Reductions of Carboxylic Acid Derivatives

Reductions of carboxylic acid derivatives might be expected to lead either to aldehydes or alcohols, functional groups having a lower oxidation state of the carboxyl carbon. that carboxylic acids themselves are reduced to alcohols by lithium aluminum hydride. At this point it will be useful to consider three kinds of reductions: (i) catalytic hydrogenation (ii) complex metal hydride reductions ...

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...