The Oppenauer Oxidation

Abstract

The application of the reduction of aldehdyes and ketones has been reviewed in an earlier chapter (The Meerwin‐Pondorff‐Verley reduction). The reversible nature of the reaction was demonstrated by Verley, but it was not until 1937 that Oppenauer showed that unsaturated steroid alcohols could be oxidized to the corresoponding ketones in excellent yield using aluminum t‐butoxide. In the presence of a large amount of acetones. Acetone functions as the hydrogen acceptor and the large excess serves to shift the equilibrium into the desired direction. This reaction is called the Oppenauer reaction hand is useful in steroid chemistry. The Oppenauer oxidation employs mild conditions so it will undoubtedly find use in synthetic organic chemistry. The recent experimental modifications are discussed here.

Isodesmic Reactions in Catalysis – Only the Beginning?

“…Traditionally, this reaction effects the interconversion of alcohols and aldehydes or ketones but, latterly, this paradigm has been extended to reversibly transfer hydrogen from a simple alkane to an alkene . Notable examples include the complementary Oppenauer oxidation and Meerwein‐Ponndorf‐Verley reduction and the Noyori hydrogenation …”

A Regioselective Synthesis of E-Guggulsterone

“…During the course of our synthetic studies of bioactive compounds, we discovered a stereoselective two-step reaction for the preparation of E -guggulsterone from 16,17-epoxypregnenolone ( 2 ) through a hydrazine reduction [ 11 , 14 ] and Oppenhauer oxidation [ 15 , 16 ]. Herein, we report a regioselective method for the preparation of E -guggulsterone and methods for the conversion of E -guggulsterone into the corresponding Z isomer ( Scheme 1 ).…”

Recent Development in the Synthesis and Catalytic Application of Iridacycles

“…Since TH often involves the dehydrogenation of the hydrogen donor isopropanol, it is not surprising that cyclometallated iridium complexes have been explored for catalytic dehydrogenation of alcohols, although many methodologies are available for the oxidation of alcohols [96–100] . Dieguez et al.…”