Silyl enol ether formation
4 real reactions from the literature, on six-membered cyclic ketones, five-membered cyclic ketones and methyl ketones. Each scheme shows starting materials, conditions and products, with the yield and reference where the source reports them.
Loading examples…
-
Silyl enol ether formation: 2-hydroxycyclohexan-1-one (a six-membered cyclic ketone) with 1) 2 eq LiTMP; 2) 2 eq TMSCl gives 1,2-bistrimethylsilyloxy cyclohexene (the silyl enol ether) and 1,2-bis(trimethylsilyloxy)-2-cyclohexene (the silyl enol ether). 15% yield.
-
Silyl enol ether formation: methyl 3-oxopyrrolidine-1-carboxylate (a five-membered cyclic ketone) with Method A: 1.1 eq LDA -78 C then TMSCl (50%); Method B: 0.8 eq variant (63%) gives the silyl enol ether and the silyl enol ether. 50-63% yield.
-
Silyl enol ether formation: 1-[benzyl(methyl)amino]propan-2-one (a methyl ketone) with Method A: ketone to 1.1 eq LDA at -78 C then TMSCl (kinetic, 75%); Method B: 0.8 eq variant (thermodynamic) gives the silyl enol ether and the silyl enol ether.
-
Silyl enol ether formation: 2-hydroxycyclohexan-1-one (a six-membered cyclic ketone) with excess Et3N / TMSCl, reflux gives 1,2-bistrimethylsilyloxy cyclohexene (the silyl enol ether) and 1,2-bis(trimethylsilyloxy)-2-cyclohexene (the silyl enol ether). 67% yield.