(Trimethylsilyl)acetic acid is an organosilicon compound utilized in organic synthesis as a building block for introducing the (trimethylsilyl)methyl (TMS-CH₂−) functionality. It is particularly valuable in Peterson olefination reactions, where its anion adds to carbonyl compounds to form β-hydroxysilanes that eliminate to yield alkenes, enabling stereoselective alkene synthesis from aldehydes and ketones. The compound also serves as a precursor for generating stabilized carbanions in aldol-type additions and in the preparation of α-silyl esters or acids. Due to the labile silyl group, it facilitates deprotection strategies in multi-step syntheses. Commonly applied in pharmaceutical and agrochemical research for creating complex intermediates with high purity and selectivity.