Recent advances in the semi-pinacol rearrangement of α-hydroxy epoxides and related compounds

Abstract

The semi-pinacol rearrangement is fast becoming an extremely reliable reaction in organic synthesis allowing the rapid construction of relatively complex stereodefined products in high yield. Recent advances in asymmetric synthesis have also enabled enantiopure precursors to partake in the rearrangement showing that extremely high levels of stereospecificity are observed. In this critical review recent advances in the semi-pinacol rearrangement over the past 15 years are examined which demonstrate the extremely high utility of this reaction towards the development of structurally diverse organic building blocks (74 references).

Asymmetric Synthesis of d-ribo-Phytosphingosine from 1-Tetradecyne and (4-Methoxyphenoxy)acetaldehyde

“…Although this reaction was not very clean, alternative methods, such as Ti(O- i -Pr) 2 (N 3 ) 2 ,27 were not attempted because in our prior experience this reagent gave rise to many unidentified compounds,10,28 including the Ti-catalyzed semi-pinacol rearrangement product of α-hydroxy epoxides 29…”

Copper‐Catalyzed Cyanomethylation of Allylic Alcohols with Concomitant 1,2‐Aryl Migration: Efficient Synthesis of Functionalized Ketones Containing an α‐Quaternary Center

“…[16] In contrast, electron-poor aryl groups migrate preferentially in neophyl rearrangements involving radical intermediates. Interestingly, the reaction of electron-rich 2-methyl-1,1-di-ptolylprop-2-en-1-ol with acetonitrile furnished migration product 2 f in lower yield (48 %).…”

Organoiodine‐Catalyzed Enantioselective Alkoxylation/Oxidative Rearrangement of Allylic Alcohols

“…[1] In most cases,t he reactions are usually initiated by either the protonation, halogenation, expoxidation, or arylation of the double bond and further driven by aring-strain-releasing process,therefore representing unconventional strategies for the difunctionalization of alkenes.Over the last decade,the enantioselective rearrangement of allylic alcohols has been extensively investigated, benefiting from the rapid growth of asymmetric catalysis (Scheme 1a). [1] In most cases,t he reactions are usually initiated by either the protonation, halogenation, expoxidation, or arylation of the double bond and further driven by aring-strain-releasing process,therefore representing unconventional strategies for the difunctionalization of alkenes.Over the last decade,the enantioselective rearrangement of allylic alcohols has been extensively investigated, benefiting from the rapid growth of asymmetric catalysis (Scheme 1a).…”