An environmentally benign catalytic oxidation of cholesteryl acetate with molecular oxygen by using N-hydroxyphthalimide
作者:Zhen Yao、Xingbang Hu、Jianyong Mao、Haoran Li
DOI:10.1039/b915737a
日期:——
A green and effective method is reported for the oxidation of cholesterylacetate to 7-keto-cholesteryl acetate with O2 in the presence of catalytic amounts of N-hydroxyphthalimide (NHPI) under mild conditions. It was found that Co(OAc)2 could cooperate with Mn(OAc)2 to enhance the catalytic ability of NHPI resulting in better yields. This economical and environmentally-friendly method provides a potentially
Cooperative Noncovalent Interactions Lead to a Highly Diastereoselective Sulfonyl-Directed Fluorination of Steroidal α,β-Unsaturated Hydrazones
作者:Joseph N. Capilato、Maxime A. Siegler、Rozhin Rowshanpour、Travis Dudding、Thomas Lectka
DOI:10.1021/acs.joc.0c02716
日期:2021.1.1
A series of steroidal α,β-unsaturated hydrazones is presented whose behavior and reactivity are governed by various types of weak C–H hydrogen bonds. Several interesting features in a representative X-ray crystal structure and 1H NMR spectrum are examined that provide evidence for a unique bifurcated intramolecular C–H interaction. Moreover, these steroid derivatives undergo functionalization in the
提出了一系列甾族α,β-不饱和,其行为和反应性受各种类型的弱C–H氢键控制。考察了代表性X射线晶体结构和1 H NMR光谱中的几个有趣特征,这些特征为独特的分叉分子内C–H相互作用提供了证据。而且,这些类固醇衍生物以高度区域选择性和立体选择性氟化的形式进行官能化。提出了磺酰氧原子通过C–H氢键引导氟化试剂。
[EN] PREPARATION OF 7-DEHYDROCHOLESTEROL USING SPECIFIC AROMATIC SOLVENTS<br/>[FR] PRÉPARATION DE 7-DÉSHYDROCHOLESTÉROL À L'AIDE DE SOLVANTS AROMATIQUES SPÉCIFIQUES
申请人:DSM IP ASSETS BV
公开号:WO2021213984A1
公开(公告)日:2021-10-28
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).