Conversion of α,β-epoxysilanes to silyl enol ethers; an unprecedented stereochemical result

Stereochemical Control in Organic Synthesis Using Silicon-Containing Compounds

“…An exceptional situation arises when the β-silyl alcohol also has an α-hydroxyl group, as with the diastereoisomeric pair of diols 5 and 6 . Treating these diols with potassium hydride, followed by trimethylsilyl chloride, gave in each case largely the product of anti elimination, 9 (5:1) from 5 and 10 (2:1) from 6 (Scheme ) . The mechanism appears to involve attack of the α-alkoxide ion on the silyl group, known as the Brook rearrangement, coupled with anti elimination of the β-hydroxide ion, summarized as 7 and 8 , respectively, instead of the usual attack of the β-alkoxide ion.…”

αβ-Epoxysilanes as precursors of carbonyl compounds and heteroatom-substituted alkenes

“…The vinylsilane (18) The second point of interest is that activated silanes such as (19) are converted directly into the carbonyl compound by treatment with buffered m-chloroperbenzoic acid in dichloromethane, presumably by acid-catalysed rearrangement of the intermediate oxirane in a manner similar to that just discussed. The vinylsilane (18) The second point of interest is that activated silanes such as (19) are converted directly into the carbonyl compound by treatment with buffered m-chloroperbenzoic acid in dichloromethane, presumably by acid-catalysed rearrangement of the intermediate oxirane in a manner similar to that just discussed.…”

Radical Brook Rearrangements: Concept and Recent Developments

“…[1] Since its discovery by Gilman and co-workers [2][3][4] and a further accurate understanding by Brook [5] in the 1950s, the Brook rearrangement, which transfers a silyl group from a carbon to an oxygen atom along with migration of charge to afford a carbon anion from the initial alkoxide species, has been established as a useful synthetic tool in organic chemistry. [6][7][8][9][10] For example, the groups of Hudrlik, [11] Kuwajima, [12] Reich, [13] González-Nogal, [14] Fleming, [15] and others [1] reported elegant methods involving Brook rearrangements to procedure olefin derivatives. Takeda, Yoshii et al developed several interesting [3+2] [16] and [3+4] [17] annulation reactions.…”