Brook rearrangement isomerization

Nucleophilic substitution of a,/3-epoxysilanes followed by the Peterson elimination is valuable for the stereoselective synthesis of alkenes.3 The reactions with lithium phenylsulfide and diphenylphosphide form alkenyl sulfides and alkenylphosphines, respectively, in a stereospecific manner. 7-Metallo-a,/ -epoxysilanes are isomerized to a-siloxyallylmetals by anionic ring opening and subsequent Brook rearrangement (Equation... 

Isomerizations, Under PTC conditions (presence of tetrahexylammonium bromide) 1,3-diaryIpropynes can be isomerized to diarylallenes by KOH at room temperature.A Brook rearrangement of acylsilanes occurs upon addition of cyanide ion. ... 

Treatment of a-methoxy- -hydroxyalkylsilanes 203a and 203b with KOBu in aqueous DMSO yields the methoxy alcohols 204a and 204b, respectively, with high isomeric purity (Scheme 2.129) [20]. The protodesilylation involved in the homo-Brook rearrangement takes place with completely stereospedfic retention of configuration at carbon. 

Shifts of atoms or groups in fluorine-containing aromatic or heteroaromatic compounds are covered in this section. Shifts due to valence isomerization (benzene-Dewar benzene-prismane-benzvalene), however, are covered in Section 5.3.4.3. A major review1 on polyfluoroaromatic and heteroaromatic compounds has been written by G.M. Brooke, one of the principal contributors in this area, covering the literature until the end of 1995 (see pp 56-59 of ref 1 for the section on rearrangement reactions). 

Recently we have observed that jS-ketosilanes, but not /3-ketogermanes, can be isomerized thermally to the analogous oxyalkenes (57). This kind of rearrangement had previously been proposed by Brook and Pierce to... 

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