(4R)-tert-Butyldimethylsilyl 4-((3S,9R,10S,13R,14R,17R)-10,13-dimethyl-3-((tetrahydro-2H-pyran-2-yl)oxy)-2,3,4,5,6,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl)pentanoate 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.