2393-53-5Relevant articles and documents
Synthesis of 14?-cyanomethyl derivatives of estradiol and the estimation of their antineoplastic activity in vitro
Baranovsky,Bil'Dyukevich,Golubeva,Kuzmitsky,Mamchits
, p. 83 - 92 (2016)
14?-Cyanomethyl derivatives of estrone and estradiol have been synthesized starting from 3-benzoyloxyestra-1,3,5(10),14,16-pentaen-17-yl acetate. A comparative study of their cytotoxicity in breast carcinoma ZR-75-1, cervix uteri carcinoma M-HeLa, uterus
Hydrogen-bond-assisted transition-metal-free catalytic transformation of amides to esters
Huang, Changyu,Li, Jinpeng,Wang, Jiaquan,Zheng, Qingshu,Li, Zhenhua,Tu, Tao
, p. 66 - 71 (2020/11/18)
The amide C-N cleavage has drawn a broad interest in synthetic chemistry, biological process and pharmaceutical industry. Transition-metal, luxury ligand or excess base were always vital to the transformation. Here, we developed a transition-metal-free hydrogen-bond-assisted esterification of amides with only catalytic amount of base. The proposed crucial role of hydrogen bonding for assisting esterification was supported by control experiments, density functional theory (DFT) calculations and kinetic studies. Besides broad substrate scopes and excellent functional groups tolerance, this base-catalyzed protocol complements the conventional transition-metal-catalyzed esterification of amides and provides a new pathway to catalytic cleavage of amide C-N bonds for organic synthesis and pharmaceutical industry. [Figure not available: see fulltext.]
Photo-Fries Rearrangement of Some 3-Acylestrones in Homogeneous Media: Preparative and Mechanistic Studies
Quindt, Matías I.,Gola, Gabriel F.,Ramirez, Javier A.,Bonesi, Sergio M.
, p. 7051 - 7065 (2019/06/18)
Irradiation of a series of 3-acylestrones under a nitrogen atmosphere in cyclohexane, acetonitrile (MeCN), and methanol (MeOH) was investigated under steady-state conditions. The molecules underwent the photo-Fries rearrangement, with concomitant homolytic fragmentation of the ester group and [1;3]-acyl migration. This pathway afforded the ortho-acyl estrone derivatives, the main photoproducts, together with estrone. During the irradiation of 3-benzoyl estrone, epimerization of estrone through the Norrish type I reaction occurred, providing lumiestrone as the photoproduct. This photoreaction involves the fragmentation of the C-α at the carbonyl group (C-17) of the steroid. On the other hand, epimerization of ortho-regioisomer 2-acetyl estrone occurred during the irradiation of 3-acetyl estrone. Photosensitization with acetone and chemical quenching with N,N,N,N-tetramethyldiazetinedioxide of the photo-Fries reaction confirmed that the photoreaction took place from the singlet excited state while the Norrish type I reaction proceeds efficiently from the triplet excited state. Solvent effects, as well as the nature of the acyl group on the photoreactions, were also studied.
Transition-Metal-Free Esterification of Amides via Selective N-C Cleavage under Mild Conditions
Li, Guangchen,Lei, Peng,Szostak, Michal
supporting information, p. 5622 - 5625 (2018/09/25)
A general, transition-metal-free, and operationally simple method for esterification of amides by a highly selective cleavage of N-C(O) bonds under exceedingly mild conditions is reported. The reaction is characterized by broad substrate scope and excellent functional group tolerance. The potential of this mild esterification is highlighted by late-stage diversification of natural products and pharmaceuticals. Conceptually, the metal-free acyl functionalization of amides represents a significant step forward as a practical alternative to ligand exchange in acylmetal intermediates.
PROCESS FOR THE PREPARATION OF ESTETROL
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Page/Page column 29; 30, (2015/04/15)
The invention relates to a process for obtaining Estetrol or a salt or solvate thereof, the process comprising: a) reacting a compound of formula (IV) or a salt or solvate thereof, wherein R1 is a hydroxyl protecting group selected from a silyl ether, an ether, an ester, a carbamate and a carbonate, and R2 is a hydroxyl protecting group selected from an ether, with an oxidizing agent selected from OsO4 or a source of osmium tetroxide to produce Estetrol or a compound of formula (II) or a salt or solvate thereof wherein R1 is as defined previously; and b) if a compound of formula (II) is obtained in step a), deprotecting said compound to produce Estetrol.
