133908-07-3

Basic information

• Product Name: 4A,23,24-TRIMETHYLCHOLESTANE
• Synonyms: DINOSTERANE;4A,23,24-TRIMETHYLCHOLESTANE
• CAS NO: 133908-07-3
• Molecular Formula: C30H54
• Molecular Weight: 414.74976
• Mol File: 133908-07-3.mol

Chemical Properties

• Appearance: /
• CAS DataBase Reference: 4A,23,24-TRIMETHYLCHOLESTANE(CAS DataBase Reference)
• NIST Chemistry Reference: 4A,23,24-TRIMETHYLCHOLESTANE(133908-07-3)
• EPA Substance Registry System: 4A,23,24-TRIMETHYLCHOLESTANE(133908-07-3)

Safety Data

• Hazardous Substances Data: 133908-07-3(Hazardous Substances Data)

Upstream product

• 148552-86-7 (20R,23S,24R)-5α-dinosteran-29-ol mesylate 
• 563-80-4 3-methyl-butan-2-one 
• 145-13-1 Pregnenolone 
• 86361-91-3 Methyl 3,4-dimethyl-2-pentenoate 
• 20817-72-5 (22E)-stigmasta-4,22-dien-3-one 
• 2415-36-3 (3S,8S,9S,10R,13S,14S,17S)-10,13-dimethyl-17-(2-methyl-1,3-dioxolan-2-yl)-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol 
• 978-98-3 20-ethylenedioxy-4-pregnen-3-one 
• 146201-28-7 4α-methyl-20-methylene-5α-pregnane 
• 146201-26-5 4α-methyl-5α-pregnan-20-one ethylene ketal 
• 146201-27-6 4α-methyl-5α-pregnan-20-one 
• 146201-34-5 (20R,22E,24R)-4α-methyl-5α-stigmast-22-ene 
• 146201-23-2 4α-methyl-5α-pregnane-3,20-dione 20-ethylene ketal 
• 146201-22-1 4-((phenylthio)methyl)-4-pregnene-3,20-dione 20-ethylene ketal 
• 146201-33-4 (20R,22E,24R)-4-((phenylthio)methyl)-4,22-stigmastadien-3-one 

Relevant articles and documents

Synthesis of Biological Markers in Fossil Fuels. 7. Selected Diastereomers of 4α-Methyl-5α-stigmastane and 5α-Dinosterane

Efficient routes for the preparation of selected C-23 and C-24 diastereomers of the C30 biological markers 4α-methyl-5α-stigmastane (1) and 5α-dinosterane (2) involved the alkylation of 20-(iodomethyl)-4α-methyl-5α-pregnane with either saturated or α,β-unsaturated esters.The alkylation of (20S)-20-(iodomethyl)-4α-methyl-5α-pregnane with methyl (3R)-3-ethyl-4-methylpentanoate furnished methyl (20R,23ξ,24S)-4α-methyl-5α-stigmastane-23-carboxylate, and a subsequent decarbomethoxylation provided (20R,24R)-1.The alkylation of (20S)-20-(iodomethyl)-4α-methyl-5α-pregnane with methyl (3S)-3,4-dimethylpentanoate led to methyl (20R,23ξ,24R)-4α,24-dimethyl-5α-cholestane-23-carboxylate, and the reduction of this mixture provided principally (20R,23S,24R)-5α-dinosteran-29-ol.The further reduction of the mesylate of this isomer secured (20R,23S,24R)-5α-dinosterane (2a).The application of the same sequence of reactions using methyl (3R)-3,4-dimethylpentanoate led principally to (20R,23R,24S)-5α-dinosterane (2d).The alkylation of (20S)-20-(iodomethyl)-4α-methyl-5α-pregnane with methyl (2ξ)-3,4-dimethyl-2-pentanoate and a subsequent reduction of the ester provided a separable mixture of (20R,23R)- and (20R,23S)-5α-dinoster-24(28)-en-29-ol in a 2.4:1 ratio.The conversion of (20R,23R)-5α-dinoster-24(28)-en-29-ol to the corresponding tert-butyldimethylsilyl ether, reduction of the Δ24(28) bond with hydrogen over platinum oxide, and deprotection gave principally (20R,23R,24R)-5α-dinosteran-29-ol.The further reduction of this alcohol provided (20R,23R,24R)-5α-dinosterane (2b).The application of the same sequence of reactions to (20R,23S)-5α-dinoster-24(28)-en-29-ol provided (20R,23S,24S)-5α-dinosterane (2c).Diastereoselectivity at the C-23 position in these ester alkylations was examined as a function of stereochemistry at both the C-20 and C-24 positions.

A synthesis of C-23 and C-24 diastereomers of 5α-dinosterane

Stereoselective routes for the preparation of C-23 and C-24 diastereomers of the C30 biological marker, 5α-dinosterane (1), involved the alkylation of (20S)-20-(iodomethyl)-4α-methyl-5α-pregnane (7) with either a saturated ester, methyl 3,4-dim