2857-42-3Relevant academic research and scientific papers
Synthesis of estrone via a thallium(III)-mediated fragmentation of a 19-hydroxy-androst-5-ene precursor
Kocovsky,Baines
, p. 6139 - 6140 (1993)
Estrone (6) has been synthesized from 1, an industrial precursor of androstane steroids, in seven steps. Key features of the strategy include the functionalization of C-19 (1 → 2) and a stereoelectronically controlled, Tl(III)-mediated degradation (2 → 3). Oppenauer oxidation of diol 4 then gave the unsaturated hydroxyketone 5, acid treatment of which induced aromatization affording 6.
Site-Selective Acylation of Natural Products with BINOL-Derived Phosphoric Acids
Li, Junqi,Grosslight, Samantha,Miller, Scott J.,Sigman, Matthew S.,Toste, F. Dean
, p. 9794 - 9799 (2019/10/14)
The site-selective acylation of a steroidal natural product 19-hydroxydehydroepiandrosterone catalyzed by 1,1′-Bi(2-napthol)-derived (BINOL) chiral phosphoric acids (CPAs) is described. Systematic variation and multivariate linear regression analysis reve
Facile Access to Bridged Ring Systems via Point-to-Planar Chirality Transfer: Unified Synthesis of Ten Cyclocitrinols
Wang, Yu,Ju, Wei,Tian, Hailong,Sun, Suyun,Li, Xinghui,Tian, Weisheng,Gui, Jinghan
supporting information, p. 5021 - 5033 (2019/03/26)
Bridged ring systems are found in a wide variety of biologically active molecules including pharmaceuticals and natural products. However, the development of practical methods to access such systems with precise control of the planar chirality presents considerable challenges to synthetic chemists. In the context of our work on the synthesis of cyclocitrinols, a family of steroidal natural products, we herein report the development of a point-to-planar chirality transfer strategy for preparing bridged ring systems from readily accessible fused ring systems. Inspired by the proposed pathway for biosynthesis of cyclocitrinols from ergosterol, our strategy involves a bioinspired cascade rearrangement, which enabled the gram-scale synthesis of a common intermediate in nine steps and subsequent unified synthesis of 10 cyclocitrinols in an additional one to three steps. Our work provides experimental support for the proposed biosynthetic pathway and for the possible interrelationships between members of the cyclocitrinol family. In addition to being a convenient route to 5(10→19)abeo-steroids, our strategy also offers a generalized approach to bridged ring systems via point-to-planar chirality transfer. Mechanistic investigations suggest that the key cascade rearrangement involves a regioselective ring scission of a cyclopropylcarbinyl cation rather than a direct Wagner-Meerwein rearrangement.
Synthetic study of strongylophorines: stereoselective construction of the characteristic lactone bridge
Oikawa, Yuya,Uchiyama, Daiki,Shirasawa, Takuya,Oikawa, Masato,Ishikawa, Yuichi
supporting information, p. 3949 - 3951 (2016/08/09)
Herein, we report an efficient construction of the lactone bridge of strongylophorine-2, which is a meroditerpenoid isolated from Strongylophora durissima and an inhibitor for HIF-1 transcriptional pathway. Starting from dehydroepiandrosterone acetate, the characteristic lactone has been constructed in 5.4% over 18 steps by employing, (1) modified oxy radical-mediated C–H functionalization at the C24 methyl group, and (2) four-step manipulation of C4 quaternary carbon stereogenic center. The lactone synthesized here is expected as a precursor for (8-desmethyl)strongylophorine-2 which is of particular interest in terms of structure–activity relationships in the inhibition of HIF-1 transcriptional pathway.
COMPOUNDS AND METHODS FOR TREATING NEOPLASIA
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Page/Page column 94, (2012/02/13)
The invention features compounds, pharmaceutical compositions and methods useful for the treatment of neoplasia. In particular embodiments, the compounds of the invention are useful for the treatment of multidrug resistant neoplasia.
The effect of 4beta and 19 ester functionalities on some electrophilic addition reactions of delta5-steroids.
Ruddock,Reese
, p. 812 - 819 (2007/10/03)
The reactions of 3beta-acyloxyandrost-5-enes with bromine/silver acetate (Petrow reaction) and mercury(II) trifluoroacetate (modified Treibs oxidation) have been used previously to effect allylic oxidation on these substrates en route to biologically active compounds. In both these reactions, which involve electrophilic addition to the delta5-bond, the 3-acyloxy substituent plays a significant role. In this report, the effect of introducing other substituents proximate to the delta5-bond has been studied by using derivatives of 3beta-acetoxyandrost-5-en-17-one (1), namely, 3beta,4beta-diacetoxyandrost-5-en-17-one (13), 3beta,19-diacetoxyandrost-5-en-17-one (14), 3beta-acetoxyandrost-5-ene-7,17-dione (15), and 3beta-acetoxy-4,4-dimethylandrost-5-en-17-one (17). Our results indicate that in both sets of reactions the effect of the introduced functional groups was pronounced. In the Petrow reaction, electrophilic addition rather than allylic oxidation on the diacetates was observed. With the Treibs reaction, allylic oxidation on the diacetates occurred. The 7-keto and 4,4-dimethyl steroids proved to be poor substrates in both reactions.
19-Oxygenated-5α-androstanes for the enhancement of libido
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, (2008/06/13)
Derivatives of 19-oxygenated-5α-androstanes are described which are useful in enhancing the libido and related psychic attitudes in mammals.
