Phenyl vinyl ether, hydrolysis

In contrast to the thermal solvolysis, a rearranged enol ether 45 (and also the hydrolysis product, acetophenone) is formed in addition to the unrearranged product 44. The rearrangement is more apparent in less nucleophilic TFE. The results are best accounted for by heterolysis to give the open primary styryl cation 46 (Scheme 8). This cation gives products of substitution 44 and elimination 30 by reaction with the solvent. Alternatively, 46 can rearrange to the a-phenyl vinyl cation 47 via 1,2-hydride shift, which gives rise to 45 and 30. 

Treatment of a,a-dicyanoalkyl phenyl selenide (14) with vinyl ether initiated by AIBN under benzene refluxing conditions generates methyl ketone (15) (eq. 4.8). An electrophilic a,a-dicyanoalkyl radical is first formed, and then it adds to vinyl ether, followed by hydrolysis. Diethyl 3-iodoalkylphosphonate (17) can be formed through AIBN-initiated addition reaction of diethyl 1-iodomethylphosphonate (16) to alkene (eq. 4.9). This is an atom-transfer reaction. Both reactions (eqs. 4.8 and 4.9) do not require Bu3SnH. 

Next, different olefins were tested in the coupling of 4-biphenyl triflate (Table 6.4). Introducing an isobutyl side chain on the vinyl ether did not affect the catalytic efficiency forming the 4-phenyl acetophenone in excellent yields after hydrolysis (entry 1). Employing a sterical encumbered vinyl ether or the cyclic olefin 2,3-dihydrofuran lowered the yield dramatically (entries 2 and 3). Moreover,... 

Methyl enol ethers of acyl silanes have been prepared in good yield by the silyla-tion of vinyl lithium reagents derived from methyl enol ethras . Indeed, po-haps the simplest preparation of a methyl enol ether of an acyl silane results from addition of a-methoxyvinyl lithium to chlorotrimethylsilane. Acid hydrolysis gave acetyl trimethyl-silane in ca 80% yield . A similar reaction has been carried out with phenyl methyl (-butyl chlorosilane. Again, acid hydrolysis gave the acyl silane, which is of course chiral at silicon . ... 

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