128-33-6

Basic information

• Product Name: 5-alpha-cholesta-8,24-dien-3-beta-ol
• Synonyms: 5-alpha-cholesta-8,24-dien-3-beta-ol;(3S,5S,10S,13R,14R,17R)-10,13-dimethyl-17-[(2R)-6-methylhept-5-en-2-yl]-2,3,4,5,6,7,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol;zymosterol intermediate 2;5α-Cholesta-8,24-dien-3β-ol;C05437;delta8,24-Cholestadien-3beta-ol
• CAS NO: 128-33-6
• Molecular Formula: C₂₇H₄₄O
• Molecular Weight: 384.63766
• EINECS: 204-880-9
• Mol File: 128-33-6.mol
• Article Data: 4

Chemical Properties

• Melting Point: 110°C
• Boiling Point: 451.27°C (rough estimate)
• Flash Point: 209.1°C
• Appearance: /
• Density: 0.9717 (rough estimate)
• Vapor Pressure: 2.45E-11mmHg at 25°C
• Refractive Index: 1.5100 (estimate)
• CAS DataBase Reference: 5-alpha-cholesta-8,24-dien-3-beta-ol(CAS DataBase Reference)
• NIST Chemistry Reference: 5-alpha-cholesta-8,24-dien-3-beta-ol(128-33-6)
• EPA Substance Registry System: 5-alpha-cholesta-8,24-dien-3-beta-ol(128-33-6)

Safety Data

• Hazardous Substances Data: 128-33-6(Hazardous Substances Data)

Usage

Description

5-alpha-cholesta-8,24-dien-3-beta-ol, also known as zymosterol, is a sterol intermediate in the biosynthesis of cholesterol (C432501). It plays a crucial role in the production of cholesterol, which is a vital component of all biological membranes, including the brain, where it constitutes approximately 25% of the total lipid content. Zymosterol has been identified in the plasma membrane of cultured human fibroblasts through labeling studies.

Uses

Used in Pharmaceutical Industry:
5-alpha-cholesta-8,24-dien-3-beta-ol is used as a key intermediate in the synthesis of cholesterol for various pharmaceutical applications. Cholesterol serves as a fundamental component of biological membranes, providing structural integrity and regulating the passage of molecules across the membrane. It also plays a role in the production of essential hormones and bile acids.
Used in Research and Development:
5-alpha-cholesta-8,24-dien-3-beta-ol is utilized as a research tool for studying the biosynthesis of cholesterol and its role in various cellular processes. Understanding the function and regulation of zymosterol can contribute to the development of targeted therapies for conditions related to cholesterol metabolism and homeostasis.
Used in Cell Biology:
In cell biology, 5-alpha-cholesta-8,24-dien-3-beta-ol is used as a marker for the plasma membrane of cultured human fibroblasts. This application aids in the study of membrane dynamics, cellular processes, and the role of cholesterol in cellular functions.
Used in Drug Delivery Systems:
Although not explicitly mentioned in the provided materials, zymosterol could potentially be used in the development of drug delivery systems, similar to gallotannin, to improve the delivery, bioavailability, and therapeutic outcomes of cholesterol-lowering drugs or other compounds targeting cholesterol-related pathways.

InChI: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

Synthetic route

3β-tert-butyldimethylsilyloxy-5α-cholesta-8,24-diene (463932-47-0) → zymosterol (128-33-6)

Conditions	Yield
With tetrabutyl ammonium fluoride In tetrahydrofuran at 20℃; for 24h;	97%

(3β,5α)-Cholesta-8,24-dien-3-ol benzoate (117168-33-9) → zymosterol (128-33-6)

Conditions	Yield
With sodium methylate In methanol	95%
With diisobutylaluminium hydride In hexane; dichloromethane at 0℃; for 0.25h;	90%

triphenylphosphonio-1-methylethanide (16666-80-1) + (3S,5S,10S,13R,14R,17R)-17-((R)-3-[1,3]Dioxolan-2-yl-1-methyl-propyl)-10,13-dimethyl-2,3,4,5,6,7,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol (118506-15-3) → zymosterol (128-33-6)

Conditions	Yield
In tetrahydrofuran

(3β,5α,24R,S)-Cholesta-8,14-diene-3,24-diol 3-benzoate 24-trifluoroacetate (117438-79-6, 117438-82-1) → zymosterol (128-33-6) + (3β,5α)-Cholesta-8(14),24-dien-3-ol (117556-83-9)

Conditions	Yield
Yield given. Multistep reaction. Yields of byproduct given;

ethanol (64-17-5) + 24ξ,25-dibromo-5α-cholesten-(8)-ol-(3β) + activated zinc-powder → zymosterol (128-33-6)

24ξ,25-dibromo-5α-cholesten-(8)-ol-(3β) + acetic acid (64-19-7) + zinc-powder → zymosterol (128-33-6)

3β-hydroxy-5α-chol-8-en-24-oic acid methyl ester (463932-43-6) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: 93 percent / imidazole / dimethylformamide / 12 h / 20 °C 2.1: 87 percent / diisobutylaluminum hydride / toluene / 1 h / -78 °C 3.1: butyllithium / tetrahydrofuran; hexane 3.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 4.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme
Multi-step reaction with 5 steps 1.1: 93 percent / imidazole / dimethylformamide / 12 h / 20 °C 2.1: 10 percent / diisobutylaluminum hydride / toluene / 1 h / -78 °C 3.1: 67 percent / DMSO; oxalyl chloride; triethylamine / CH2Cl2 / 0.92 h / -78 - -20 °C 4.1: butyllithium / tetrahydrofuran; hexane 4.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 5.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme

3β-tert-butyldimethylsilyloxy-5α-chol-8-en-24-al (463932-46-9) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: butyllithium / tetrahydrofuran; hexane 1.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 2.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme

3β-tert-butyldimethylsilyloxy-5α-chol-8-en-24-oic acid methyl ester (463932-44-7) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: 87 percent / diisobutylaluminum hydride / toluene / 1 h / -78 °C 2.1: butyllithium / tetrahydrofuran; hexane 2.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 3.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme
Multi-step reaction with 4 steps 1.1: 10 percent / diisobutylaluminum hydride / toluene / 1 h / -78 °C 2.1: 67 percent / DMSO; oxalyl chloride; triethylamine / CH2Cl2 / 0.92 h / -78 - -20 °C 3.1: butyllithium / tetrahydrofuran; hexane 3.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 4.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme

3β-tert-butyldimethylsilyloxy-5α-chol-8-en-24-ol (463932-45-8) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: 67 percent / DMSO; oxalyl chloride; triethylamine / CH2Cl2 / 0.92 h / -78 - -20 °C 2.1: butyllithium / tetrahydrofuran; hexane 2.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 3.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme

3β-benzoyloxy-5α-chol-8-en-24-oic acid ethyl ester (463932-42-5) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 5 steps 1.1: 86 percent / potassium hydroxide / tetrahydrofuran / 5 h / 20 °C 2.1: 93 percent / imidazole / dimethylformamide / 12 h / 20 °C 3.1: 87 percent / diisobutylaluminum hydride / toluene / 1 h / -78 °C 4.1: butyllithium / tetrahydrofuran; hexane 4.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 5.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme
Multi-step reaction with 6 steps 1.1: 86 percent / potassium hydroxide / tetrahydrofuran / 5 h / 20 °C 2.1: 93 percent / imidazole / dimethylformamide / 12 h / 20 °C 3.1: 10 percent / diisobutylaluminum hydride / toluene / 1 h / -78 °C 4.1: 67 percent / DMSO; oxalyl chloride; triethylamine / CH2Cl2 / 0.92 h / -78 - -20 °C 5.1: butyllithium / tetrahydrofuran; hexane 5.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 6.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme

3β-benzoyloxy-15α-hydroxy-5α-chol-8-en-24-oic acid ethyl ester (463932-39-0) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 7 steps 1.1: 99 percent / 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 12 h / 0 °C 2.1: 75 percent / tri-n-butyltin hydride; α,α'-azobisisobutyronitrile / toluene / 90 °C 3.1: 86 percent / potassium hydroxide / tetrahydrofuran / 5 h / 20 °C 4.1: 93 percent / imidazole / dimethylformamide / 12 h / 20 °C 5.1: 87 percent / diisobutylaluminum hydride / toluene / 1 h / -78 °C 6.1: butyllithium / tetrahydrofuran; hexane 6.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 7.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme
Multi-step reaction with 8 steps 1.1: 99 percent / 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 12 h / 0 °C 2.1: 75 percent / tri-n-butyltin hydride; α,α'-azobisisobutyronitrile / toluene / 90 °C 3.1: 86 percent / potassium hydroxide / tetrahydrofuran / 5 h / 20 °C 4.1: 93 percent / imidazole / dimethylformamide / 12 h / 20 °C 5.1: 10 percent / diisobutylaluminum hydride / toluene / 1 h / -78 °C 6.1: 67 percent / DMSO; oxalyl chloride; triethylamine / CH2Cl2 / 0.92 h / -78 - -20 °C 7.1: butyllithium / tetrahydrofuran; hexane 7.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 8.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme

3β-benzoyloxy-15α-phenyloxythiocarbonyloxy-5α-chol-8-en-24-oic acid ethyl ester (463932-41-4) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 6 steps 1.1: 75 percent / tri-n-butyltin hydride; α,α'-azobisisobutyronitrile / toluene / 90 °C 2.1: 86 percent / potassium hydroxide / tetrahydrofuran / 5 h / 20 °C 3.1: 93 percent / imidazole / dimethylformamide / 12 h / 20 °C 4.1: 87 percent / diisobutylaluminum hydride / toluene / 1 h / -78 °C 5.1: butyllithium / tetrahydrofuran; hexane 5.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 6.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme
Multi-step reaction with 7 steps 1.1: 75 percent / tri-n-butyltin hydride; α,α'-azobisisobutyronitrile / toluene / 90 °C 2.1: 86 percent / potassium hydroxide / tetrahydrofuran / 5 h / 20 °C 3.1: 93 percent / imidazole / dimethylformamide / 12 h / 20 °C 4.1: 10 percent / diisobutylaluminum hydride / toluene / 1 h / -78 °C 5.1: 67 percent / DMSO; oxalyl chloride; triethylamine / CH2Cl2 / 0.92 h / -78 - -20 °C 6.1: butyllithium / tetrahydrofuran; hexane 6.2: 87 percent / tetrahydrofuran; hexane / 1 h / 0 °C 7.1: 97 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 24 h / 20 °C View Scheme

(3β,5α,24R,S)-Cholest-8-ene-3,24-diol 3-benzoate (117151-68-5) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 2 steps 1: 90 percent / 6H5C(CF3)2O>S(C6H5)2 / CH2Cl2 / 0.02 h / 0 °C 2: 95 percent / NaOMe / methanol View Scheme
Multi-step reaction with 2 steps 1: 87 percent / Martin sulfurane / CH2Cl2 / 0.25 h / 0 °C 2: 90 percent / dibal / CH2Cl2; hexane / 0.25 h / 0 °C View Scheme

(3β,5α,24R,S)-24-<(tert-Butyldimethylsilyl)oxy>cholest-8-en-3-ol benzoate (117151-67-4) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 3 steps 1: 100 percent / Bu4NF / tetrahydrofuran / 25 °C 2: 90 percent / 6H5C(CF3)2O>S(C6H5)2 / CH2Cl2 / 0.02 h / 0 °C 3: 95 percent / NaOMe / methanol View Scheme
Multi-step reaction with 3 steps 1: 99 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 12 h / Ambient temperature 2: 87 percent / Martin sulfurane / CH2Cl2 / 0.25 h / 0 °C 3: 90 percent / dibal / CH2Cl2; hexane / 0.25 h / 0 °C View Scheme

(3β,5α,15α,24R,S)-24-<(tert-Butyldimethylsilyl)oxy>-cholest-8-ene-3,15-diol 3-benzoate (117439-11-9, 117604-43-0) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 5 steps 1: pyridine 2: NaOMe / methanol; toluene / 25 °C 3: 100 percent / Bu4NF / tetrahydrofuran / 25 °C 4: 90 percent / 6H5C(CF3)2O>S(C6H5)2 / CH2Cl2 / 0.02 h / 0 °C 5: 95 percent / NaOMe / methanol View Scheme
Multi-step reaction with 5 steps 1: pyridine, 4-(N,N-dimethylamino)pyridine / 12 h / 25 °C 2: 92 percent / Bu3SnH, AIBN / toluene / 0.33 h / 90 °C 3: 99 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 12 h / Ambient temperature 4: 87 percent / Martin sulfurane / CH2Cl2 / 0.25 h / 0 °C 5: 90 percent / dibal / CH2Cl2; hexane / 0.25 h / 0 °C View Scheme

C47H68O5SSi (117439-12-0, 117439-13-1) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 4 steps 1: NaOMe / methanol; toluene / 25 °C 2: 100 percent / Bu4NF / tetrahydrofuran / 25 °C 3: 90 percent / 6H5C(CF3)2O>S(C6H5)2 / CH2Cl2 / 0.02 h / 0 °C 4: 95 percent / NaOMe / methanol View Scheme
Multi-step reaction with 4 steps 1: 92 percent / Bu3SnH, AIBN / toluene / 0.33 h / 90 °C 2: 99 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / 12 h / Ambient temperature 3: 87 percent / Martin sulfurane / CH2Cl2 / 0.25 h / 0 °C 4: 90 percent / dibal / CH2Cl2; hexane / 0.25 h / 0 °C View Scheme

3-methyl-butan-2-one (563-80-4) + <3-nitro-phenyl>-hydrazine hydrochloride → zymosterol (128-33-6)

Conditions

Yield

Multi-step reaction with 8 steps 1: 1.) n-butyllithium, diisopropylamine / 1.) hexane, THF, -78 deg C, 15 min, 2.) THF, -78 deg C to 0 deg C, 1h 2: 98 percent / p-TSA, MgSO4 / toluene; CHCl3 / 3 h / 70 °C 3: 100 percent / H2 / Lindlar / toluene; CHCl3 / 12 h / 760 Torr 4: tert-butylamine-borane complex / CH2Cl2 / 1 h / Heating 5: 92 percent / pyridine, 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 0.2 h / 0 °C 6: 96 percent / 2,6-di-tert-butyl-4-methylpyridine / CH2Cl2 / 1.) room temp., overnight, 2.) reflux, 30 min 7: 98 percent / tributylamine, 98percent formic acid / Pd(OAc)2(Ph3P)2 / dimethylformamide / 0.5 h / 70 °C View Scheme

(3β,5α,22E)-3-(benzoyloxy)ergosta-8(14),22-dien-15-one (36071-76-8) → zymosterol (128-33-6)

Conditions

Yield

Multi-step reaction with 9 steps 1: 75 percent / O3 / CH2Cl2 / -78 °C 2: 1.) n-butyllithium, diisopropylamine / 1.) hexane, THF, -78 deg C, 15 min, 2.) THF, -78 deg C to 0 deg C, 1h 3: 98 percent / p-TSA, MgSO4 / toluene; CHCl3 / 3 h / 70 °C 4: 100 percent / H2 / Lindlar / toluene; CHCl3 / 12 h / 760 Torr 5: tert-butylamine-borane complex / CH2Cl2 / 1 h / Heating 6: 92 percent / pyridine, 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 0.2 h / 0 °C 7: 96 percent / 2,6-di-tert-butyl-4-methylpyridine / CH2Cl2 / 1.) room temp., overnight, 2.) reflux, 30 min 8: 98 percent / tributylamine, 98percent formic acid / Pd(OAc)2(Ph3P)2 / dimethylformamide / 0.5 h / 70 °C View Scheme

(3β,5α,20S)-3-(benzoyloxy)-15-oxopregn-8(14)-ene-20-carboxaldehyde (117151-64-1) → zymosterol (128-33-6)

Conditions

Yield

Multi-step reaction with 8 steps 1: 1.) n-butyllithium, diisopropylamine / 1.) hexane, THF, -78 deg C, 15 min, 2.) THF, -78 deg C to 0 deg C, 1h 2: 98 percent / p-TSA, MgSO4 / toluene; CHCl3 / 3 h / 70 °C 3: 100 percent / H2 / Lindlar / toluene; CHCl3 / 12 h / 760 Torr 4: tert-butylamine-borane complex / CH2Cl2 / 1 h / Heating 5: 92 percent / pyridine, 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 0.2 h / 0 °C 6: 96 percent / 2,6-di-tert-butyl-4-methylpyridine / CH2Cl2 / 1.) room temp., overnight, 2.) reflux, 30 min 7: 98 percent / tributylamine, 98percent formic acid / Pd(OAc)2(Ph3P)2 / dimethylformamide / 0.5 h / 70 °C View Scheme

Benzoic acid (3S,5S,9R,10S,13R,17R)-17-((R)-4-hydroxy-1,5-dimethyl-hexyl)-10,13-dimethyl-15-oxo-2,3,4,5,6,7,9,10,11,12,13,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-yl ester (117438-91-2, 117438-92-3) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 4 steps 1: 92 percent / pyridine, 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 0.2 h / 0 °C 2: 96 percent / 2,6-di-tert-butyl-4-methylpyridine / CH2Cl2 / 1.) room temp., overnight, 2.) reflux, 30 min 3: 98 percent / tributylamine, 98percent formic acid / Pd(OAc)2(Ph3P)2 / dimethylformamide / 0.5 h / 70 °C View Scheme

(3β,5α)-3-(Benzoyloxy)cholest-8(14)-ene-15,24-dione (117151-69-6) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 5 steps 1: tert-butylamine-borane complex / CH2Cl2 / 1 h / Heating 2: 92 percent / pyridine, 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 0.2 h / 0 °C 3: 96 percent / 2,6-di-tert-butyl-4-methylpyridine / CH2Cl2 / 1.) room temp., overnight, 2.) reflux, 30 min 4: 98 percent / tributylamine, 98percent formic acid / Pd(OAc)2(Ph3P)2 / dimethylformamide / 0.5 h / 70 °C View Scheme

(3β,5α-22E)-3-(Benzoyloxy)cholesta-8(14),22-diene-15,24-dione (117160-80-2) → zymosterol (128-33-6)

Conditions

Yield

Multi-step reaction with 6 steps 1: 100 percent / H2 / Lindlar / toluene; CHCl3 / 12 h / 760 Torr 2: tert-butylamine-borane complex / CH2Cl2 / 1 h / Heating 3: 92 percent / pyridine, 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 0.2 h / 0 °C 4: 96 percent / 2,6-di-tert-butyl-4-methylpyridine / CH2Cl2 / 1.) room temp., overnight, 2.) reflux, 30 min 5: 98 percent / tributylamine, 98percent formic acid / Pd(OAc)2(Ph3P)2 / dimethylformamide / 0.5 h / 70 °C View Scheme

(3β,5α,22R,S)-3-(Benzoyloxy)-22-hydroxycholest-8(14)-ene-15,24-dione (117168-34-0) → zymosterol (128-33-6)

Conditions

Yield

Multi-step reaction with 7 steps 1: 98 percent / p-TSA, MgSO4 / toluene; CHCl3 / 3 h / 70 °C 2: 100 percent / H2 / Lindlar / toluene; CHCl3 / 12 h / 760 Torr 3: tert-butylamine-borane complex / CH2Cl2 / 1 h / Heating 4: 92 percent / pyridine, 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 0.2 h / 0 °C 5: 96 percent / 2,6-di-tert-butyl-4-methylpyridine / CH2Cl2 / 1.) room temp., overnight, 2.) reflux, 30 min 6: 98 percent / tributylamine, 98percent formic acid / Pd(OAc)2(Ph3P)2 / dimethylformamide / 0.5 h / 70 °C View Scheme

(3β,5α,24R,S)-3-(Benzoyloxy)-24-(trifluoroacetoxy)cholest-8(14)-en-15-one (117438-87-6, 117438-88-7) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 3 steps 1: 96 percent / 2,6-di-tert-butyl-4-methylpyridine / CH2Cl2 / 1.) room temp., overnight, 2.) reflux, 30 min 2: 98 percent / tributylamine, 98percent formic acid / Pd(OAc)2(Ph3P)2 / dimethylformamide / 0.5 h / 70 °C View Scheme

(3β,5α,24R,S)-Cholesta-8,14-diene-3,15,24-triol 3-benzoate 24-trifluoromethanesulfonate (117439-00-6, 117439-01-7) → zymosterol (128-33-6)

Conditions	Yield
Multi-step reaction with 2 steps 1: 98 percent / tributylamine, 98percent formic acid / Pd(OAc)2(Ph3P)2 / dimethylformamide / 0.5 h / 70 °C View Scheme

zymosterol (128-33-6) → 5α-cholestadien-(14.24)-one-(3)

Conditions	Yield
With chromium(VI) oxide; acetic acid at 90℃;

zymosterol (128-33-6) → 5α-cholestadien-(8.24)-one-(3) (27192-37-6)

Conditions	Yield
With cyclohexanone; aluminum isopropoxide; toluene

zymosterol (128-33-6) + cyclohexanone (108-94-1) + aluminum isopropoxide (555-31-7) + toluene (108-88-3) → 5α-cholestadien-(8.24)-one-(3) (27192-37-6)

zymosterol (128-33-6) + cyclohexanone (108-94-1) + aluminum isopropoxide (555-31-7) + benzene (71-43-2) → 5α-cholestadien-(8.24)-one-(3) (27192-37-6)

zymosterol (128-33-6) + benzoyl chloride (98-88-4) → (3β,5α)-Cholesta-8,24-dien-3-ol benzoate (117168-33-9)

Conditions	Yield
With pyridine

zymosterol (128-33-6) + aluminum isopropoxide (555-31-7) + acetone (67-64-1) + toluene (108-88-3) → 5α-cholestadien-(8.24)-one-(3) (27192-37-6)

zymosterol (128-33-6) + aluminum isopropoxide (555-31-7) + acetone (67-64-1) + benzene (71-43-2) → 5α-cholestadien-(8.24)-one-(3) (27192-37-6)

zymosterol (128-33-6) + acetic anhydride (108-24-7) → zymosteryl acetate (2579-07-9)

Conditions	Yield
With pyridine for 0.5h; Heating;

zymosterol (128-33-6) → (E)-(R)-6-((3S,5S,10S,13R,14R,17R)-3-Hydroxy-10,13-dimethyl-2,3,4,5,6,7,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl)-2-methyl-hept-2-enal (218783-16-5)

Conditions	Yield
With selenium(IV) oxide In ethanol Heating;

zymosterol (128-33-6) + S-Adenosyl-L-methionine (14031-35-7, 17176-17-9, 29908-03-0, 75044-81-4, 78548-84-2, 79647-17-9, 91279-78-6) → ergosta-8,24-diene-3-β-ol (516-86-9)

Conditions	Yield
With mutant Y81F sterol methyl transferase from Saccharomyces cerevisiae In water at 29℃; Rate constant;

zymosterol (128-33-6) + ethyl acetate (141-78-6) + platinum → 5α-cholest-8-en-3β-ol (566-97-2)

Conditions	Yield
Hydrogenation;

zymosterol (128-33-6) + acetic acid (64-19-7) + CrO3 → 5α-cholestadien-(14.24)-one-(3)

Conditions	Yield
at 90℃;

zymosterol (128-33-6) + CuO → 5α-cholestadien-(8.24)-one-(3) (27192-37-6)

Conditions	Yield
at 300℃;

diethyl ether (60-29-7) + zymosterol (128-33-6) + palladium → 5α-cholest-8(14)-en-3β-ol (566-99-4)

Conditions	Yield
Hydrogenation;

zymosterol (128-33-6) + acetic acid (64-19-7) + platinum → 5α-cholest-8(14)-en-3β-ol (566-99-4)

Conditions	Yield
Hydrogenation;

diethyl ether (60-29-7) + zymosterol (128-33-6) + acetic acid (64-19-7) + platinum → 5α-cholest-8(14)-en-3β-ol (566-99-4)

Conditions	Yield
Hydrogenation;

zymosterol (128-33-6) + acetic acid (64-19-7) + CrO3 → 5α-cholestadien-(8(14).24)-one-(3)

Conditions	Yield
at 90℃;

zymosterol (128-33-6) + ozone (10028-15-6) + acetic acid (64-19-7) → acetone (67-64-1)

diethyl ether (60-29-7) + zymosterol (128-33-6) + bromine (7726-95-6) + acetic acid (64-19-7) → zymosterol dibromide

Upstream product

• 16666-80-1 triphenylphosphonio-1-methylethanide 
• 118506-15-3 (3S,5S,10S,13R,14R,17R)-17-((R)-3-[1,3]Dioxolan-2-yl-1-methyl-propyl)-10,13-dimethyl-2,3,4,5,6,7,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol 
• 117168-33-9 (3β,5α)-Cholesta-8,24-dien-3-ol benzoate 
• 117438-79-6 (3β,5α,24R,S)-Cholesta-8,14-diene-3,24-diol 3-benzoate 24-trifluoroacetate 
• 64-17-5 ethanol 
• 64-19-7 acetic acid 
• 463932-47-0 3β-tert-butyldimethylsilyloxy-5α-cholesta-8,24-diene 
• 463932-43-6 3β-hydroxy-5α-chol-8-en-24-oic acid methyl ester 
• 463932-46-9 3β-tert-butyldimethylsilyloxy-5α-chol-8-en-24-al 
• 463932-44-7 3β-tert-butyldimethylsilyloxy-5α-chol-8-en-24-oic acid methyl ester 
• 463932-45-8 3β-tert-butyldimethylsilyloxy-5α-chol-8-en-24-ol 
• 463932-42-5 3β-benzoyloxy-5α-chol-8-en-24-oic acid ethyl ester 
• 463932-39-0 3β-benzoyloxy-15α-hydroxy-5α-chol-8-en-24-oic acid ethyl ester 
• 463932-41-4 3β-benzoyloxy-15α-phenyloxythiocarbonyloxy-5α-chol-8-en-24-oic acid ethyl ester 

Downstream Products

• 117168-33-9 (3β,5α)-Cholesta-8,24-dien-3-ol benzoate 
• 2579-07-9 zymosteryl acetate 
• 516-86-9 fecosterol 
• 566-97-2 5α-cholest-8-en-3β-ol 
• 566-99-4 5α-cholest-8(14)-en-3β-ol 
• 501915-26-0 ergosta-8,25⁽²⁷⁾-dien-3-ol 
• 71547-99-4 ergosta-8,24-dien-3β-ol 

Relevant articles and documents

A new synthesis of zymosterol

A modified scheme for the synthesis of zymosterol, one of the biosynthetically important yeast sterols, starting from 3-benzoyloxyergosta-8(14),22-dien-15-one has been suggested.

Synthesis of Zymosterol: Salient Intermediate of Fungal and Mammalian Sterol Biosynthesis

A useful strategy for the construction of sterol biosynthetic intermediates possessing Δ8-unsaturation is described and exemplified by the synthesis of zymosterol (1) and 24,25-dihydrozymosterol (2).