2309-32-2Relevant academic research and scientific papers
SYNTHESIS AND 13C-NMR ANALYSIS OF 5α- AND 5β-CHOLESTANE-3,6-DIONE
Wijnberg, Joannes B. P. A.,Groot, Aede de
, p. 333 - 344 (1989)
Starting from cholesterol a simple and efficient synthesis of 5α-cholestane-3,6-dione and 5β-cholestane-3,6-dione is described.The 13C shielding data of C-7, C-9, and C-19 in both isomers can be used in the determination of the stereochemistry at C-5 of these compounds.The combination of 13C NMR spectroscopy and the simple synthesis of both isomers offers good opportunities for the determination of the stereochemistry at C-5 of 3,6-dioxosteroids.
ELECTROOXIDATIVE SIMULATION OF STEREOSELECTIVITY IN MICROSOMAL ALLYLIC HYDROXYLATION
Shono, Tatsuya
, p. 91 - 94 (1984)
A comparison of the stereochemistry of liver microsomal γ-hydroxylation of some cyclic α,β-unsaturated ketones with that of electrochemical γ-acetoxylation of the corresponding dienol esters and with that of peracid oxidation of the dienol esters has been carried out.
Novel method for synthesizing cholesterol from 21-hydroxy-20-methylpregna-4-ene-3-ketone as raw material
-
, (2021/11/19)
The invention provides a method for synthesizing cholesterol from 21-hydroxy-20-methylpregna-4-ene-3-ketone (4-BA) as a raw material. The method comprises the step of: (1) carrying out etherification reaction, oxidation reaction, Grignard reagent addition reaction, sulfonylation reaction, reduction reaction, acetylation reaction and reduction reaction on 4-BA and triethyl orthoformate to obtain cholesterol. The synthesis method is simple in process, high in yield, low in cost, environment-friendly in process and suitable for industrial production.
Synthesis and search for 3β,3′β-disteryl ethers after high-temperature treatment of sterol-rich samples
Bus, Katarzyna,Ofiara, Karol,Sitkowski, Jerzy,Szterk, Arkadiusz,Zmys?owski, Adam
, (2020/06/08)
It has been proven that at increased temperature, sterols can undergo various chemical reactions e.g., oxidation, dehydrogenation, dehydration and polymerisation. The objectives of this study are to prove the existence of dimers and to quantitatively analyse the dimers (3β,3′β-disteryl ethers). Sterol-rich samples were heated at 180 °C, 200 °C and 220 °C for 1 to 5 h. Quantitative analyses of the 3β,3′β-disteryl ethers were conducted using liquid extraction, solid-phase extraction and gas chromatography coupled with mass spectrometry. Additionally, for the analyses, suitable standards were synthetized from native sterols. To identify the mechanism of 3β,3′β-disteryl ether formation at high temperatures, an attempt was made to use the proposed synthesis method. Additionally, due to the association of sterols and sterol derivatives with atherosclerosis, preliminary studies with synthetized 3β,3′β-disteryl ethers on endothelial cells were conducted.
Kinetics of Electrophilic Fluorination of Steroids and Epimerisation of Fluorosteroids
Rozatian, Neshat,Harsanyi, Antal,Murray, Ben J.,Hampton, Alexander S.,Chin, Emily J.,Cook, Alexander S.,Hodgson, David R. W.,Sandford, Graham
supporting information, p. 12027 - 12035 (2020/08/28)
Fluorinated steroids, which are synthesised by electrophilic fluorination, form a significant proportion of marketed pharmaceuticals. To gain quantitative information on fluorination at the 6-position of steroids, kinetics studies were conducted on enol ester derivatives of progesterone, testosterone, cholestenone and hydrocortisone with a series of electrophilic N?F reagents. The stereoselectivities of fluorination reactions of progesterone enol acetate and the kinetic effects of additives, including methanol and water, were investigated. The kinetics of epimerisation of 6β-fluoroprogesterone to the more pharmacologically active 6α-fluoroprogesterone isomer in HCl/acetic acid solutions are detailed.
Mechanism of cholesterol reduction to coprostanol by Eubacterium corpostanoligenes ASTCC 51222
Ren, Dewei,Li, Ling,Schwabacher, Alan W.,Youbg, Jerry W.,Beitz, Donald C.
, p. 33 - 40 (2007/10/03)
The mechanism of reduction of cholesterol to coprostanol by Eubacterium coprostanoligenes ATCC 51222 was studied by incubating the bacterium with a mixture of α- and β-isomers of cholesterol.Coprostanol, isolated after incubation of cholesterol in a growth medium under anaerobic conditions, retained 97percent of the tritium originally presented in cholesterol.The majority of this tritium (64percent), however, was in the C-6 position in coprostanol, which showed that the conversion of cholesterol into coprostanol by E. coprostanoligenes involved the intermediate formation of 4-cholesten-3-one followed by the reduction of the latter to coprostanol.In resting cell assays in which washed bacterial cells were incubated with micellar cholesterol in phosphate buffer at 37 deg C, both 4-cholesten-3-one and coprostanone were produced in addition to coprostanol.Furthermore, 5-cholesten-3-one, 4-cholesten-3-one, and coprostanone were converted efficiently to coprostanol by E. coprostanoligenes.These results support the hypothesis that the major pathway for reduction of cholesterol by E. coprostanoligenes involves the intermediate formation of 4-cholesten-3-one followed by reduction of the latter to coprostanol through coprostanone as an intermediate. (Steroids 61:33-40, 1996) - Key words: dual-labeled cholesterol, coprostanol; cholesterol reduction; Eubacterium; NMR.
A NEW METHOD FOR ENOL ACETYLATION
Chowdhury, P.K.,Sharma, R.P.,Barua, J.N.
, p. 3383 - 3384 (2007/10/02)
Saturated and conjugated ketones react with chlorotrimethylsilane and acetic anhydride to furnish the enol acetates in excellent yield.
The synthesis of cholesterol-2,2,4,4,6-d5
Gruenke,Cymerman Craig
, p. 495 - 500,497,498 (2007/10/13)
Cholesterol-3,4-d2 and -2,2,4,4,6-d5 have been synthesized from Δ4-cholestene-3-one for use as mass spectrometric stable isotope internal standards. Conversion of Δ4-cholesten-3-one to the enol acetate followed by reduction with sodium borodeuteride in a deuterated solvent yielded cholesterol-3,4-d2. Similarly Δ4-cholesten-3-one-2,2,4,6,6-d5 obtained by base-catalyzed exchange of Δ4-cholesten-3-one in ethanol-0-d1 was converted to the enol acetate, followed by reduction with sodium borohydride in a deuterated medium to give cholesterol-2,2,4,4,6-d5.
Stereoscopic synthesis of 4β-deutero-Δ5-3-ketosteroids
Segal,Fradkina,Torgov
, p. 213 - 216 (2007/10/13)
Simple methods for the stereospecific synthesis of 4β-deutero-Δ5-3-ketosteroids have been developed involving the reduction of 3-acetoxy-Δ3, 5-steroids with lithium aluminum hydride and subsequent decomposition with deuterium oxide a
