Propargyl sulfenate allene sulfoxide

The synthetically most useful oxygen-sulfur transpositions (equation 16) are the allyl sulfenate-allyl sulfoxide and the propargyl sulfenate-allene sulfoxide rearrangements, the driving force of both being the formation of the strong S=0 bond at the cost of the weak O—S bond (Scheme 12). ... [Pg.837]

Following studies on the rearrangement of allylic arenesulfinates, Braverman and coworkers have investigated a number of natural extensions of this unique transformation, including the predictable [2,3] sigma tropic rearrangements of allylic sulfenates to sulfoxides and of propargylic sulfenates and sulfinates to allenic sulfoxides and sulfones respectively. The last reaction is described below, while the other two are described in Chapter 14. [Pg.676]

C. [2,3]-Sigmatropic Rearrangements of Propargylic Sulfenates to Allenic Sulfoxides... [Pg.736]

Synthetic Utility of the Propargylic Sulfenate-to-Allene Sulfoxide Rearrangement... [Pg.80]

Scheme 13 [2,3]Sigmatropic rearrangements of nitroaryl propargyl sulfenates to allene sulfoxides and their cycloaddition reactions...

Allenic sulfoxides can be made from propargylic sulfenates by a 2,3-sigmatropic shift. In the example reported,the product is not stable at room temperature and undergoes a 1,5-sigmatropic hydrogen shift (Scheme 56). These allenic sulfoxides can react as Michael acceptors (Scheme 57). ... [Pg.155]

Certain sulfoxides can be prepared by rearrangement of the sulfenate esters thus, allyl arenesulfenate esters (7), obtained by condensation of the sulfenyl chloride with allyl alcohol (8), spontaneously rearrange to the allyl sulfoxides (9) (Scheme 6). The rearrangement also occurs with alkynic alcohols for instance, trichloromethanesulfenyl chloride (10) reacts with propargyl alcohol (11) to form the allenic sulfoxide (12) (Scheme 7). [Pg.69]

Analogous with the rearrangement of allylic sulfoxides is the [2,3]-sigmatropic rearrangement of propargylic sulfoxides to allenic sulfenates. This process, which has been relatively little studied so far, appears to be the first step in the facile and quantitative rearrangement of sulfoxide 98 to the hemithioacetal 101 (equation 45)167. This reaction,... [Pg.739]

Scheme 22 [2,3]Sigmatropic rearrangement of propargylic sulfoxide to allenic sulfenate...

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