3-?[[(1,?1-?Dimethylethyl)?dimethylsilyl]?oxy]?-butanoic Acid Ethyl Ester is an intermediate in synthesizing Bis(2-?butoxyethyl) 2-?(3-?Hydroxybutoxy)?ethyl Phosphate Triester (B415220), a compound derived from 2-Butoxyethanol (B692895), which is a reagent in the synthesis of 4-butoxyethoxy-N-octadecyl-1,8-naphthalimide as a new fluorescent probe for the determination of proteins. Also used as a reagent in the synthesis of 4-hydroxybenzaldehyde derivatives as tyrosinase inhibitors.