A’-Silyloxy -enone

Addition of acyl anion equivalents (propenal d reagents) to ketones provides general access to a -hy-droxy enones. In an application of this method to pentaimulation, the trimethylsilyl- or ethoxyethyl-pro-tected cyanohydrins of a, -enals were used." The derived tertiary acetates undergo elimination (p-TsOH/benzene) to the divinyl ketones which cyclize in the acidic reaction medium (equation 25)." In some cases the a -hydroxy or a -silyloxy enones underwent cyclization but in much lower yields. Substitution in the ring and on the double bonds is compatible. 

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See also in sourсe #XX -- [ , ]

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