70741-38-7

Basic information

• Product Name: (3S,10S,13R,14R,17R)-10,13-dimethyl-17-[(2R)-6-methylheptan-2-yl]-2,3,4,7,11,12,14,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-3-ol
• Synonyms: (3S,10S,13R,14R,17R)-10,13-dimethyl-17-[(2R)-6-methylheptan-2-yl]-2,3,4,7,11,12,14,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-3-ol;8-Dehydrocholesterol;cholesta-5,8-dien-3 beta-ol;8DHC;Cholesta-5,8-dien-3β-ol;Δ5,8 Sterol;Δ5,8-Cholest-dienol;cholesta-5,8(9)-dien-3-ol
• CAS NO: 70741-38-7
• Molecular Formula: C₂₇H₄₄O
• Molecular Weight: 384.63766
• Mol File: 70741-38-7.mol
• Article Data: 2

Chemical Properties

• Melting Point: 147-148 °C(Solv: chloroform (67-66-3); acetone (67-64-1))
• Boiling Point: 492.1°C at 760 mmHg
• Flash Point: 211.8°C
• Appearance: /
• Density: 1g/cm³
• Vapor Pressure: 9.51E-12mmHg at 25°C
• Refractive Index: 1.535
• Storage Temp.: -20°C Freezer
• Solubility: Chloroform (Slightly), Methanol (Slightly)
• PKA: 15.00±0.70(Predicted)
• CAS DataBase Reference: (3S,10S,13R,14R,17R)-10,13-dimethyl-17-[(2R)-6-methylheptan-2-yl]-2,3,4,7,11,12,14,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-3-ol(CAS DataBase Reference)
• NIST Chemistry Reference: (3S,10S,13R,14R,17R)-10,13-dimethyl-17-[(2R)-6-methylheptan-2-yl]-2,3,4,7,11,12,14,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-3-ol(70741-38-7)
• EPA Substance Registry System: (3S,10S,13R,14R,17R)-10,13-dimethyl-17-[(2R)-6-methylheptan-2-yl]-2,3,4,7,11,12,14,15,16,17-decahydro-1H-cyclopenta[a]phenanthren-3-ol(70741-38-7)

Safety Data

• Hazardous Substances Data: 70741-38-7(Hazardous Substances Data)

Usage

Description

8-dehydro Cholesterol (8-DHC) is an isomer of the cholesterol precursor 7-DHC . It accumulates in tissues and plasma in patients with Smith-Lemli-Opitz syndrome (SLOS), a disorder characterized by a mutation in DHCR7, the gene encoding 3β-hydroxysterol-Δ7-reductase, and decreased cholesterol levels in bodily tissues and fluids, as well as microcephaly, intellectual disability, and distinctive dysmorphic features. 8-DHC levels are increased in serum in a rat model of SLOS induced by the DHCR7 inhibitor AY 9944 .

Uses

8-Dehydrocholesterol is an intermediate in the synthesis of Zymostenol, which is the derivative of Zymosterol (Z701520), an sterol intermediate in the biosynthesis of cholesterol (C432501).

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/h9,18-19,21,23-24,28H,6-8,10-17H2,1-5H3/t19-,21+,23-,24?,26+,27-/m1/s1

Synthetic route

3β-benzoyloxy-cholesta-5,8-diene (53435-19-1) → cholesta-5,8(9)-dien-3β-ol (70741-38-7)

Conditions	Yield
With potassium hydroxide; benzene

7α-cholesta-5,8-dien-3β-yl acetate (3914-89-4) → cholesta-5,8(9)-dien-3β-ol (70741-38-7)

Conditions	Yield
With lithium In various solvent(s) at -20℃; 30 min longer than required for the initial apperance of a blue color; Yield given;

7-Dehydrocholesteryl acetate (1059-86-5) → cholesta-5,8(9)-dien-3β-ol (70741-38-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: benzene / 4 h / Heating 2: Li / various solvent(s) / -20 °C / 30 min longer than required for the initial apperance of a blue color View Scheme

7α-bromocholest-5-en-3β-ol benzoate (26048-46-4) → cholesta-5,8(9)-dien-3β-ol (70741-38-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: ammonium thiocyanate; acetone 2: benzene; methanol. KOH View Scheme
Multi-step reaction with 2 steps 1: pyridine 2: benzene; methanol. KOH View Scheme

7β-bromocholest-5-en-3β-ol benzoate (65942-28-1) → cholesta-5,8(9)-dien-3β-ol (70741-38-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: pyridine 2: benzene; methanol. KOH View Scheme

7-dehydrocholesterol (434-16-2) → cholesta-5,8(9)-dien-3β-ol (70741-38-7)

Conditions	Yield
Stage #1: 7-dehydrocholesterol With diethylazodicarboxylate In toluene at 116℃; for 0.75h; Molecular sieve; Microwave irradiation; Stage #2: With propylamine; lithium; ethylenediamine at 0℃; for 0.25h;	79 mg

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → cholesta-5,8-dien-3-one (259659-60-4)

Conditions	Yield
With oxalyl dichloride; dimethyl sulfoxide; triethylamine In dichloromethane at -50℃; for 1h; Oxidation;	83%

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → 1,6-cyclo-1,10-seco-cholesta-5,7,9-trien-3ξ-ol (1249-85-0, 1249-86-1)

Conditions	Yield
With mercury(II) diacetate; toluene-4-sulfonic acid Irradiation;

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → cholesta-4,8-dien-3-one (209850-55-5)

Conditions	Yield
With aluminum isopropoxide; acetone; benzene

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → cholesta-5,8-dien-3β-ol acetate (17137-76-7)

Conditions	Yield
With pyridine; acetic anhydride

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → 5α-cholest-8-en-3β-ol (566-97-2)

Conditions	Yield
With hydrogen; nickel In ethanol Yield given;

cholesta-5,8(9)-dien-3β-ol (70741-38-7) + acetic anhydride (108-24-7) → cholesta-5,8-dien-3β-ol acetate (17137-76-7)

Conditions	Yield
In pyridine

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → cholesta-5,8-dien-3α-ol

Conditions	Yield
Multi-step reaction with 2 steps 1: 83 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / 1 h / -50 °C 2: [3H]NaBH4; NaBH4 / ethanol / 10 h / 20 °C View Scheme

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → [3β-3H]cholesta-8-dien-3α-ol

Conditions	Yield
Multi-step reaction with 2 steps 1: 83 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / 1 h / -50 °C 2: [3H]NaBH4 / ethanol / 1 h / 20 °C View Scheme

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → [3α-3H]cholesta-8-dien-3β-ol

Conditions	Yield
Multi-step reaction with 2 steps 1: 83 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / 1 h / -50 °C 2: [3H]NaBH4; NaBH4 / ethanol / 10 h / 20 °C View Scheme
Multi-step reaction with 2 steps 1: 83 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / 1 h / -50 °C 2: [3H]NaBH4 / ethanol / 1 h / 20 °C View Scheme

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → C30H51(3)HOSi

Conditions	Yield
Multi-step reaction with 3 steps 1: 83 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / 1 h / -50 °C 2: [3H]NaBH4 / ethanol / 1 h / 20 °C 3: pyridine / 2 h / 50 °C View Scheme

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → [3,3']bicholesta-3,5,8-trienyl (903507-08-4)

Conditions	Yield
Multi-step reaction with 3 steps 1: acetone; aluminium isopropylate; benzene 2: sodium-amalgam 3: acetic acid; acetic acid anhydride; CHCl3 View Scheme

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → 3ξH,3'ξH-[3,3']bicholesta-4,8-dienyl-3,3'-diol (903507-11-9)

Conditions	Yield
Multi-step reaction with 2 steps 1: acetone; aluminium isopropylate; benzene 2: sodium-amalgam View Scheme

diethylaluminium cyanide (1188327-50-5) + 8α,9α-epoxycholest-5-en-3β-ol (209850-60-2) + cholesta-5,8(9)-dien-3β-ol (70741-38-7) → Cholesta-5,8,14-triene-3β-ol (209850-45-3)

Conditions	Yield
With m-chloroperoxybenzoic acid In dichloromethane; toluene

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → 3β,5α,9α-trihydroxycholesta-7-en-6-one (1210058-93-7) + 3β-hydroxycholesta-5,8-dien-7-one (96974-03-7)

Conditions	Yield
With Methyl linoleate; 2,2’-azobis(4-methoxy-2,4-dimethyl)valeronitrile; Tocopherol In benzene at 37℃; for 2h;

cholesta-5,8(9)-dien-3β-ol (70741-38-7) → 5α,6α-epoxycholesta-7-en-3β,9α-diol (1210058-89-1) + 5α,9α-epidioxy-8α,14α-epoxycholesta-6-en-3β-ol (1210058-91-5) + 5α,9α-epidioxycholesta-7-en-3β,6β-diol (1210059-16-7) + 5α,9α-epidioxycholesta-7-en-3β,6α-diol (1210058-90-4) + 3β,5-dihydroxy-5α-cholesta-7,9(11)-diene-6-one (133565-76-1)

Conditions	Yield
With Methyl linoleate; 2,2’-azobis(4-methoxy-2,4-dimethyl)valeronitrile In benzene at 37℃; for 1h;

Upstream product

• 434-16-2 7-dehydrocholesterol 
• 65942-28-1 7β-bromocholest-5-en-3β-ol benzoate 
• 26048-46-4 7α-bromocholest-5-en-3β-ol benzoate 
• 1059-86-5 7-Dehydrocholesteryl acetate 
• 3914-89-4 7α-cholesta-5,8-dien-3β-yl acetate 
• 53435-19-1 3β-benzoyloxy-cholesta-5,8-diene 

Downstream Products

• 566-97-2 5α-cholest-8-en-3β-ol 

Relevant articles and documents

Comprehensive gas chromatography-electron ionisation mass spectrometric analysis of fatty acids and sterols using sequential one-pot silylation: Quantification and isotopologue analysis

RATIONALEFatty acids and sterol lipids play crucial roles in several biological processes and several biological facts underline the interconnection between these lipid classes. Therefore, it is of interest to develop a comprehensive method analysing both classes in the form of their most favourable derivatives suitable for quantification and isotopologue analysis. METHODSLipids were derivatised by a sequential one-pot procedure using N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MtBSTFA) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). No clean-up or concentration steps were necessary. The prepared samples were directly available for gas chromatography-electron ionisation mass spectrometric (GC-EI-MS) analysis on a standard column. For quantification, the SIM mode was used and for isotopologue analysis scheduled scan mode was applied. RESULTSDevelopment of a sequential one-pot derivatisation for GC-EI-MS allowing comprehensive analysis of fatty acids and sterols as their most favourable derivatives. Validation carried out using human plasma, comparison with certified NIST plasma. LLOQ of usually 3.3 ng/mL achieved. Isotopologue analysis of 2-[13C]-acetate incorporation in HL-60 cells proving feasibility of method. CONCLUSIONSThe presented method successfully combines two consecutive silylation reactions in one pot, enabling the analysis of both fatty acids and sterols in a comprehensive analytical method. The method has great potential for the quantification of lipids as well as the comprehensive study of both biochemical pathways, using [13C]-flux analysis. Copyright