TBDMS-(3β)-3-[(Tetrahydro-2H-pyran-2-yl)oxy]- 7-carbonyl-chol-5-en-24-oic Acid is an intermediate in the synthesis of 5α-Cholesta-7,24-diene-3β-ol (C431505), which is the derivative of Zymosterol (Z701520). It can also be used for identification of a new plasma biomarker of Alzheimer's disease using metabolomics technology.