Allylvinyl ethers

While not a hydrocarbon rearrangement, the 3,3-shift of allylvinyl ethers to y,S-... 

Supportive of the suggestion that ionization is not a major pathway in the Claisen rearrangement of the parent compound is the fact that the SDKIEs in aqueous solution are comparable to those in the gas phase and in m-xylene. Furthermore, attempts to solvolyze 1,1-dideuterioaUyl mesylate in aqueous methanol resulted in no ionization to an allyl cation instead, the direct displacement product was formed exclusively. Finally, determinations of a solvent kinetic isotope effect in deuterium oxide resulted in values around unity 10%. ° In the solvolysis reaction of tert-butyl chloride the value is 40% at room temperature. " It is possible to cause allylvinyl ethers to ionize by providing cation stabilizing substituents and Lewis acids or Lewis acidic solvents. ... 

Twenty-seven years later. Saucy [4] described a new kind of Qaisen rearrangement that occurred after condensation in acidic medium between a propargyUc or allyHc alcohol and vinyl ether affording propargylvinyl or allylvinyl ether, respectively. In the later case, y-unsaturated ketones are isolated in good yields after rearrangement (Scheme 6.1). 

Z-selectivity has been observed by Yamamoto during aluminum-derivative-catalyzed allylvinyl ether rearrangement, see K. Maruoka, K. Nanoshita,... 

Finally, as mentioned in Chapter 8, aliphatic allylvinyl ethers are in equilibrium with the corresponding 4-pentenals (the parent is shown in Scheme 8.1(10 and the scheme is repeated here as Scheme 9.30). The position of the equilibrium can be adjusted catalyticaUy. 

The feasibility of enantioselective catalysis in on-column reaction chromatography was exemplified by the Gosteli-Claisen rearrangement of allylvinyl ethers (cf. 

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