Zymosterol is an intermediate in cholesterol biosynthesis. Disregarding some intermediate compounds (e.g. 4-4-dimethylzymosterol) lanosterol can be considered a precursor of zymosterol in the cholesterol synthesis pathway. The conversion of zymosterol into cholesterol happens in the endoplasmic reticulum. Zymosterol accumulates quickly in the plasma membrane coming from the cytosol. The movement of zymosterol across the cytosol is more than twice as fast as the movement of cholesterol itself.

Zymosterol

Names
IUPAC name 5α-Cholesta-8,24-dien-3β-ol
Systematic IUPAC name (1R,3aR,5aS,7S,9aS,11aR)-9a,11a-Dimethyl-1-[(2R)-6-methylhept-5-en-2-yl]-2,3,3a,4,5,5a,6,7,8,9,9a,10,11,11a-tetradecahydro-1H-cyclopenta[a]phenanthren-7-ol
Identifiers
CAS Number	128-33-6 Y
3D model (JSmol)	Interactive image
ChemSpider	83724 N
ECHA InfoCard	100.004.438
PubChem CID	92746
UNII	PU2755PT4O Y
InChI InChI=1S/C27H44O/c1-18(2)7-6-8-19(3)23-11-12-24-22-10-9-20-17-21(28)13-15-26(20,4)25(22)14-16-27(23,24)5/h7,19-21,23-24,28H,6,8-17H2,1-5H3/t19-,20+,21+,23-,24+,26+,27-/m1/s1 N Key: CGSJXLIKVBJVRY-XTGBIJOFSA-N N InChI=1/C27H44O/c1-18(2)7-6-8-19(3)23-11-12-24-22-10-9-20-17-21(28)13-15-26(20,4)25(22)14-16-27(23,24)5/h7,19-21,23-24,28H,6,8-17H2,1-5H3/t19-,20+,21+,23-,24+,26+,27-/m1/s1 Key: CGSJXLIKVBJVRY-XTGBIJOFBJ
SMILES O[C@H]4CC[C@@]3(/C2=C(/[C@@H]1CC[C@H]([C@H](C)CC\C=C(/C)C)[C@@]1(C)CC2)CC[C@H]3C4)C
Properties
Chemical formula	C27H44O
Molar mass	384.64 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references