4-(Trimethylsiloxy)-3-penten-2-one (trimethylsilyl ether of acetylacetone) has been used in the synthesis of isomers of organosilicon carbofunctional compounds:4-(3′-triethoxysilylpropylimino)pent-2-en-2-ol4-(3′-triethoxysilylpropylamino)pent-3-en-2-one