434-16-2Relevant articles and documents
Oxidation of cholesterol by a biomimetic oxidant, cetyltrimethylammonium dichromate
Patel, Sabita,Mishra
, p. 3522 - 3526 (2006)
The oxidation of cholesterol by cetyltrimethylammonium dichromate (CTADC) in dichloromethane (DCM) yielded 7-dehydrocholesterol, while with addition of acetic acid in DCM the product was found to be 5-cholesten-3-one. The kinetics of oxidation of cholesterol by CTADC in DCM, in the presence of acid, was investigated with change in [acid], [cholesterol], [CTADC], [surfactant], temperature, and solvents. The reaction was found to be first order with acetic acid and fractional order with CTADC and cholesterol. Michaelis-Menten-type kinetics was observed with respect to cholesterol. The solvent isotope effect was found to be k(D2O)/k(H2O) = 0.72. The observed experimental data suggest that the reaction occurs in reversed micellar system, akin to an enzymatic environment, and the reaction path involves the intermediate formation of an ester complex, which undergoes decomposition to give the product.
Preparation method of 7-dehydrocholesterol for production of vitamin D3
-
, (2021/04/07)
The invention particularly discloses a preparation method of 7-dehydrocholesterol for production of vitamin D3. The preparation method comprises the following steps: an esterification reaction, a bromination reaction, a debromination reaction and a saponification hydrolysis reaction. The esterification reaction comprises the following steps: adding cholesterol, an acid-binding agent and a solid catalyst into petroleum ether, carrying out heating to 45-50 DEG C in a nitrogen atmosphere, dropwise adding benzoyl chloride, performing heating to 78-82 DEG C after dropwise adding, conducting stirring for a reaction for 3-5 hours, adding distilled water to quench the reaction, performing filtering to obtain filter residues and a filtrate, extracting the filter residues with distilled water, concentrating an oil layer, then adding acetone, carrying out a reflux reaction for 30-40 minutes, conducting cooling to 20-30 DEG C, and performing filtering to obtain cholesterol benzoate; and soaking, filtering and drying the filter residues to obtain a solid desiccant, and repeatedly using the solid desiccant. The method has the advantage of facilitating cyclic utilization of the catalyst.
PREPARATION OF 7-DEHYDROCHOLESTEROL USING SPECIFIC AROMATIC SOLVENTS
-
, (2021/10/30)
The present invention relates to a new synthesis of 7- dehydrocholesterol or itsOH-protected forms of the formula I by the reaction of a compound of formula (ll)in the presence of a solvent of formula (III), comprising the step (a) wherein a salt of the formula (II) is added to a solvent of the formula (III) at a temperature of between 60 °C and the boiling point of said solvent. This process leads to a significant reduction in the level of the by-product of formula (V).