Alkynones silyl enol ethers

Drouin, Conia et al. have found that these reactions can be carried out under even milder conditions by cyclization of silyl enol ethers of alkynones. Treatment of (194), as an (E)-(Z) mixture, with HgCb in CH2CI2 in the presence of hexamethyldisilazene for 30 min at 30 C gives vinylmercurial (195 R = HgCl) in quantitative yield. Cleavage of the carbon-mercury bond can be carried out to give (195 R - H, D, CQzMe, Br or COMe). 

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