It is shown that (2)-2-hydroxy 2, Cdienes (2-dienols), formed by photoenolization of the@- akyl-a,@-unsatuated ketones la-e, can be trapped by a silylating reagent to give the (2)-2- trimethylsiloxy 2, 4-dienes 2a-e. This corresponds to stereoselective and regioselective production of just one of the three isomeric silyl dienol ethers which can be formed from each of these ketones. In contrast, silylation of the same ketones under thermal conditions ...
