Metal enolates are an important class of reactive intermediates widely employed in organic synthesis. In contrast, little is known about silenolates, the silicon analogues of enolates. Enolates exist in two tautomeric forms, the enol form and the keto form, and their reactions reflect the coexistence of these two forms. The dominant structure of alkali metal enolates is the enol form both in nonsolvating media and in various solvating media such as THF, N,N,N’,N’-tetramethylethylenediamine, and [18]crown-6. Silenolates also exist in two tautomeric forms: the keto form a (acyl silyl anion) and the enol form b (silene) [Eq. (1)], and they also show ambident reactivity. The first silenolate (solvated), recently isolated and characterized by X-ray crystallography, has the keto form a. An enol-form silenolate bwas not yet reported. Isolation of an enol-form silenolate is challenging, because it has a Si=C p bond which is thermodynamically and kinetically less stable than a C=C bond. In addition, enol-form silenolates can be regarded as functional silenes, which are reagents of growing importance in silicon chemistry. Here we report the synthesis, isolation, and X-ray molecular structure of the first enol-form silenolates (tBuMe2Si)2Si=C(OLi)Ad (1) and (tBu2MeSi)2Si=C(OLi)Ad (2). We show by DFT quantum-mechanical calculations that, in contrast to organic enolates, which exist predominantly in the enol form regardless of solvation, the structure of silenolates 1 and 2 is strongly dependent on the solvent. Silenolate 1 was synthesized by metal–halogen exchange between tBuMe2SiLi (in excess) and bromo acyl silane Br(tBuMe2Si)2SiC(O)Ad (3) in hexane at 78 8C. Upon warming to room temperature pale yellow crystals of silenolate 1 precipitated (10% yield). The major product is substitution product 4 [Eq. (2)].