首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Zusammenfassung Die Synthese von 3, 16-Diacetoxy-5 -pregnan-20-on (VI) aus 3-Acetoxy-5 -pregn-16-en-20-on und eine verbesserte Darstellung von 3, 16-Diacetoxy-5 -pregnan-20-on (III) aus 3-Acetoxy-pregna-5, 16-dien-20-on werden beschrieben.  相似文献   

2.
On treatment with methylmagnesium iodide, 3β-acetoxy-5β,6β-epoxy-16α,17α-cyclo-hexapregnan-20-one undergoes 3-O-deacetylation along with the opening of the 5β,6β-epoxide ring to form 5α-methyl-6β-hydroxy steroid and the 6α-methyl-6β-hydroxy isomer, the 20-keto group remaining intact.  相似文献   

3.
汪涛  丁兰  郭国聪 《结构化学》2007,26(4):457-461
6β,7β,14β-Trihydroxy-1α-acetoxy-7α,20-epoxy-ent-kaur-16-en-15-one was isolated from the natural plant of Isodon japonica (Burm.f), Haravar. galaucocalyx (maxim) Hara. The structure was elucidated by means of spectral and chemical studies. In addition, its crystal was determined by single-crystal X-ray diffraction analysis. It crystallizes in triclinic, space group P1, Z = 2, a = 6.3506(4), b = 13.5766(8), c = 15.2777(9) , α = 80.506(1), β = 83.856(1), γ = 88.307(1)o, C25H36O9, Mr = 480.54, V = 1291.64(13) 3, Z = 2, Dc = 1.236 g/cm3, F(000) = 516, μ = 0.093 mm-1, S = 0.988, the final R = 0.0761 and wR = 0.1955. Flack factor is 0.02(19), and the largest peak and deepest hole on the final difference Fourier map are 0.556 and –0.265 e/3, respectively. The X-ray diffraction shows the existence of intermolecular C–H…O (DA) hydrogen bonds between adjacent molecules.  相似文献   

4.
A preparative method was proposed for the preparation of pregn-4-ene-9,16,17-triol-3,20-dione 16,17-acetonide (2) from 5-H-pregn-16-en-3-ol-20-one (1). The key stage in the proposed sequence of the reactions is the microbiological 9-hydroxylation and introduction of the 4-en-3-one grouping into the molecule of1 by R- and S-dissociative forms of the Rhodococcus sp. strain.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1898–1901, August, 1992.  相似文献   

5.
A calculation has been made by the method of molecular mechanics, using the MM2 program, of a number of stereomeres of 1,5,6,7(H)- and 1,5,6,7(H)-guai-11(13)-en-6,12-olides. The possibilities of the adoption by the seven-membered ring of particular conformations according to the type of its linkage with the 5-membered carbocycle have been considered. Questions of the influence of the orientation of the Me groups on the degree of distortion of the conformation of the seven-membered ring from the ideal and the relative stabilities of the various conformers are discussed.A. N. Nesmeyanov Institute of Organometallic Compounds, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 198–203, March–April, 1991.  相似文献   

6.
The structure of the title compound (1) has been studied by means of X-ray diffraction. The region of cycleD in epoxide1 was compared with that of the 16,17-epoxy derivatives of progesterone and pregnenolone (studied previously) as well as with that of the respective 16,17- and 16,17-cyclopropano analogs. In contrast to the 16,17-epoxy-20-oxo derivatives, in compound1 the electron conjugation of the epoxide ring with the CH3CO group at C(17) is partly disrupted. Moreover, the steric congestion at C(17) is significantly less pronounced in 16,17-epoxide1 than in its 16,17-counterpart. Both of these factors, especially steric decongestion, are favorable for nucleophilic attack at C(17) in the molecule of1. The X-ray diffraction data do not contradict the previously advanced mechanism of epoxide ring opening in 16,17- and 16,17-epoxy-20-oxo steroids by nucleophilic reagents.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 401–405, February, 1993.  相似文献   

7.
1975年Varg ftig等发现,3α-氨基-2β-羟基-5α-雄甾-17-酮盐酸盐(Org 6001)具有抗心律失常作用,它不仅口服有效,疗效优于利多卡因,而且无激素活性,被认为是一类新型结构的抗心律失常药。以后,人们又对Org 6001进行了一系列的结构改造工作,但  相似文献   

8.
本文报道了3α-氨基-2β,17β-二羟基-16β-哌啶基-5α-雄甾烷和2β-氨基-3α,17β-二羟基-16β-哌啶基-5α-雄甾烷的合成方法。  相似文献   

9.
Stereoisomers of 1,5,6,7(H)- and 1,5,6,7(H)-guai-11(13)-en-6,12-olides are calculated using molecular mechanics. The possibility of forming various conformations in the 7-membered ring is examined as a function of the fusion to the 5-membered C-ring. The effect of the methyl orientation on the conformation of the 7-membered ring and the relative stability of the conformers are discussed.Insitute of Phytochemistry, Karaganda, fax (3212)-43-37-73. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 54–56, January–February, 2000.  相似文献   

10.
New esters of 3β,5α,6β-trihydroxysteroids and 3β,5-dihydroxy-6-ketosteroids containing 6-chloropyridine groups characteristic of the alkaloid epibatidine were synthesized by acylation with 6-chloronicotinoylchloride. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 175-179, March-April, 2009.  相似文献   

11.
Two procedures were developed for the synthesis of 17-alkyl-8,9-estra-1,3,5(10)-triene-3,14,17-triols from 3-methoxy-estra-1,3,5(10),8(9),14(15)-pentaene-17-one (1) using photosensitized oxidation by atmospheric oxygen or ionic hydrogenation in the presence of oxygen. It was shown that 17-hexynyl-8,9-estra-1,3,5(10)-triene-3,14,17-triol (23) and its 3-methoxy derivative (26) inhibit K+,Na+-ATPase, with inhibition degree increasing on introduction of an oxygen-containing substituent into position 17. For the first time steroids were found with 2-adrenoblocking action.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 207–212, January, 1993.  相似文献   

12.
Lutfun Nahar  Alan B Turner 《Tetrahedron》2003,59(43):8623-8628
Evidence for the presence of 3β,6α-dihydroxy-5α-chol-9(11)-en-23-one in the aglycone mixture from the starfish Marthasterias glacialis is provided by the synthesis of 3β,6α-dihydroxy-5α-cholan-23-one (19) and its identification in the hydrogenated aglycone mixture. The side-chain is constructed from the 23,24-dinorcholanol (13) by reaction of the 22-tosylate (16) with the acetylide anion, followed by hydration of the resulting 23-yne (17).  相似文献   

13.
Ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim](+)[PF(6)](-)) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim](+)[BF(4)](-)) were found to promote an unusual Wagner-Meerwein rearrangement of steroidal 16α,17α-epoxides leading to unnatural 13-epi-18-nor-16-one derivatives as the main products. These compounds were isolated in good to excellent yields. 16α-Hydroxy-Δ(13)-18-norsteroids, the results of the usual rearrangement, were obtained as minor components of the reaction mixtures. The ionic liquid [bmim](+)[PF(6)](-) was shown to induce C-ring aromatization of 16α,17α-epoxyestranes due to the formation of HF, the hydrolysis product of [PF(6)](-). Increasing amounts of HF and [PO(2)F(2)](-) were detected by (19)F and (31)P NMR when the ionic liquid was reused. The structures of the steroidal products, 16-oxo-18-nor-13α-steroid derivatives, 16α-hydroxy-Δ(13)-18-norsteroids, and C-aromatic compounds were determined by two-dimensional NMR techniques and high-resolution mass spectrometry (HRMS). The ionic liquids were recirculated efficiently.  相似文献   

14.
New steroid derivatives containing 6-chloropyridine groups characteristic of the alkaloid epibatidine and neonicotinoid insecticides were synthesized by reacting 3β,5α,6β-trihydroxysteroids or 3β,5-dihydroxy-6ketosteroids with 2-chloro-5-chloromethylpyridine. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 180-182, March-April, 2009.  相似文献   

15.
It has been established that on the interaction of the 5,6-epoxysteroids (1a–c) with trifluoroacetic acid in chloroform the 6-trifluoroacetates of the 5,6-diols (2a–c) are formed in high yield. The alkaline hydrolysis of the trifluoroacetates (2a–c) leads to the corresponding diols (3a–c).Institute of Bioorganic Chemistry, Belarus' National Academy of Sciences, 220141, Belarus', Minsk, ul. Akad. Kuprevicha, 5/2. Translated from Khimiya prirodnykh Soedinenii, No. 2, pp. 201–204, March–April, 1999.  相似文献   

16.
15,16-Methyleneprogesterone was produced from 15,16-methylene-3-hydroxyandrost-5-en-17-one with Wittig olefination of 17-ketone by methoxymethylenetriphenylphosphorane as the key stage.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 203–207, January, 1993.  相似文献   

17.
A scheme using -sitosterol as an example for synthesizing 2, 3, 14-trihydroxy-4,7-6-ketosteroids and their derivatives from 3-hydroxy-5-steroids was developed.Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, 220141, Belarus, Minsk, ul, akad. Kuprevicha, 5/2. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 244–248, May–June, 2000.  相似文献   

18.
Substituted phenyl iodides or diiodides reacted with ethyl iodotetrafluoroproponylate ICF2CF2CO2Et, 1 in the presence of copper powder to give the coupled products 2 or 3 in good yields. Addition of 1 to ethylene and allyl acetate proceeded smoothly under thermal and radical conditions to give the corresponding adducts, which underwent elimination reaction to give β-vinyl and β-allyl α,α,β,β-tetrafluoroesters, CH2CHCF2CF2CO2Et, 4 and CH2CHCH2CF2CF2CO2Et, 5, respectively. 1 also readily reacted with 1,5-hexadiene and 1-hexene with copper or palladium complex, followed by reduction to remove iodine to produce ω-alkenyl-α,α,β,β-tetrafluoroester CH2CH(CH2)4CF2CF2CO2Et 6 and α,α,β,β-tetrafluoroester C4H9CH2CHICF2CF2CO2Et.  相似文献   

19.
16α,17- and 15α,16-Epoxy derivatives of diterpenoid steviol having ent-kaurane structure were found for the first time to undergo Wagner-Meerwein rearrangement in alkaline medium or by the action of boron trifluoride-diethyl ether complex to give products with ent-beyerane structure. The geometric parameters of steviol 16α,17- and 15α,16-epoxides were determined by X-ray analysis.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号