Crystal Structure of 6β,7β,14β-Trihydroxy-1α-acetoxy-7α,20-epoxy-ent-kaur-16-en-15-one

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.     

8β-hydroxyeremophil-7(11)-ene-12,8α(4β,6α)-diolide分子的晶体结构

8β-hydroxyeremophil-7(11)-ene-12,8α(4β,6α)-diolide was isolated from the Ligularia intermedia and char- acterized by MS, multi NMR and X-ray single crystal diffraction. Its crystal structure was determined as in a orthorhombic type, with space group P212121 with a=6.8519(5), b=10.7191(8), c=18.5942(14) oA, V =1365.67(18) oA3, Z=4, and the calculated density is 1.354 mg/m3. F(000)=592, μ=0.101 mm-1.     

Preliminary Studies on Acylation of 10β-OH and 7α-OH in 7-Epi-10-deacetylpaclitaxel

Paclitaxel(=Taxol@Xl)hasbeensuccessfullyaPpliedtometaStaicovaryandbreaStcancertheraPyt'l.ThecomplexityofchemicalStructUreandreactivitiesofthisPOlyoxygenatedmoleculedreWalotofattentionfromorganicchemists.ThesecondaryhydroxylsattahedtoC-2,7,lOandl3eXhibitedvariousreaCtivitiesindifferentbaccatinIIl(2)analogsl'l.Generally,76-OHismorereactivetowardselectrophilicreagentSthanlOP-OHl'l.Thispropertyisutilhableinthepreparaionof7-TES-baccatinIlI(3),anAnportantintermediateforthesemisynthesisof…     

THE REARRANGEMENT OF 1,7β-DIMETHYL-7α-HYDROXY-8aα-CARBOXYMETHYL-9β-CARBOMETHOXY-4bα, 5, 6, 7, 8, 8a-HEXAttYDROFLUORENE LACTONE INDUCED BY DIBAL-H

1,7β- Dimethyl-7α- hydroxy-8aα-carboxymethyl-9β-carbomethoxy-4bα, 5, 6, 7, 8, 8α-hexahydrofluorene lactone(2) is converted to 8, 12-epoxyallogibberic acid methyl ester(4) by the action of diisobutyl aluminum hydride (DIBAL-H) with a novel rearrangement reaction.     

Possible conformations of the seven-membered rings and relative stabilities of 1β,5α,6β,7α(H)- and 1α,5α,6β,7α(H)-guai-11(13)-en-6,12-olides

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.     

Stereoisomerism ofβ-polyfluoroalkyl-α,β-enones

-Polyfluoroalkyl-,-enones formed in the E,Z form are converted by the action of atmospheric oxygen into a 937 mixture of E,Z and Z,E isomers in the dark and 6040 mixture of these isomers in the light. The Z isomer of 1-phenyl-4,4, 4-trifluoro-2-buten-1-one was isolated preparatively for the first time and its E conformation relative to the C-C bond was established. The Z,E isomer spontaneously transforms into the indicated equilibrium mixtures.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1685–1689, July, 1991.     

5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇的合成

以5-雄烯二醇为原料,用微生物转化的方法合成了两个重要的神经甾体5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇。所用菌种总枝毛霉为我们自己筛选,并首次应用于5-雄烯-3β, 7α, 17β-三醇和5-雄烯-3β, 7β, 17β-三醇的合成中。     

Synthesis of Novel 17α-Eethynyl-5-androstene-3β, 7β, 17β-triol (HE3286)Derivatives

以脱氢表雄酮为原料,经羟基乙酰化,羰基亚乙二氧基化,CrO3/3,5-二甲基吡啶氧化,硼氢化钠还原,脱17-位亚乙二氧基,脱3-位乙酰基,用叔丁基二甲基氯硅烷(TBDMSC1)保护3,7-OH,17-位环氧化,17-位开环,脱TBDMSC1保护等十步反应合成了四个新型的17α-乙炔基-5-雄甾烯-3β,7β,17β-三醇(HE3286)衍生物,其结构经1H NMR和MS表征.     

7α和7β-甲基-10β,17β-二乙酰氧基-Δ~4-雌甾烯-3-酮的合成

文献报道炔诺酮类或17β-羟基(乙酰氧基)-⊿~5(⊿~4)-雌(雄)甾烯-3-酮类化合物中引入7α-甲基可增强其抗生育活性队.我们曾合成10β-乙酰氧基-17β-羟基-17α-乙炔基-⊿~4-雌甾烯-3-酮,经动物试验也显示较强的抗生育活性.本文报道一个既具有10β-乙酰氧基又有7α-甲基或7β-甲基的新甾族化合物——7α和7β-甲基-10β,17β-二乙酰     

Oligomeric Derivatives of 3α,7β-D Ihydroxy-5β-Cholan-24-Oic Acid (Ursodeoxycholic Acid)

The synthesis and pharmacological evaluation of Oligomeric and polymeric derivatives of drugs is receiving increasing attention by several groups ^1-9. Usually, in these derivatives, the drug moieties are linked to a proper oligomeric or polymeric matrix by means of covalent bonds of limited stability to biological environments. This may ensure a gradual release of the active principle after introduction into the body Fluids. Poly(oxyethyleneglycol)s, as matrices, appear to be particularly promising on this respect⁷.     

7α-甲基-19-羟基-睾丸素-17β-乙酸酯用节杆菌芳构化: 7α-甲基-雌甾酚醇-17β-乙酸酯和7α-甲基-雌甾酚酮的合成

雌甾酚酮(la)和雌甾酚醇(lb)是治疗妇科病的要药。其17位的乙炔衍生物乙炔雌二醇(lc)及其3-甲醚化合物ld是甾体口服避孕药的组分。7α-甲基-雌甾酚酮(le)的生理活性比la大2～3倍,7α-甲基-乙炔雌二醇(lf)的生理活性比lb大20倍。文献报道le或7α-甲基-雌甾酚醇(lg)是由7α-甲基-△~(1,4)-3-酮或7α-甲基-△~4,6-3-酮及其相应的19-失碳甾体化合物经高温或经酸重排等方法制得;也有用节杆菌转化7α-甲基-19-失碳睾丸素而制得。所有这些合成方法不仅步骤多,而且得率往往不佳。本文报道     

High guest inclusion in 3β-amino-7α,12α-dihydroxycholan-24-oic acid enabled by charge-assisted hydrogen bonds

3β-Amino-7α,12α-dihydroxycholan-24-oic acid (2) forms inclusion compounds with high ratio (host/guest=1/4) of guest methanol. Both hydrogen bonds and hydrophobic interactions are important to the solid structure. The cholates assemble in a head-to-tail fashion to form infinite hydrogen-bonded chains. The chains are interconnected between cholates and also through the guests. Large channels are formed along the crystallographic a axis where most of the methanol molecules are located. Presence of a dominant hydrogen-bonding motif (i.e., ammonium-carboxylate ion pairing) is probably responsible for high guest incorporation.     

A Facile Synthesis of 3-Oxo-7αH-eudesma-4-ene-9β, 12-diol

3-Oxo-7αH-eudesma-4-en-9β,12-diol1awasfirstisolatedfromCassinauncatabyKingetal.,anditsstructurewasdeterminedbyhighfieldNMRtechniques;however,theabsoluteconfigurationofC-llremainedunsolved.RecentlyPedroetalreportedthefirsttotalsynthesisof(llS)-3-oxo-7aH-eudesma-4-en-95,l21bfromartemisin2inl3steps'.Herein,wereportafacileprocedureforsynthesisofC-llisomericdiolsandthestereochemistryofnaturaldiol.Oursyntheticrouteisshownasbelow:a)ref5,36%;b)Vilsmeierreagent.30%H202,CH2Cl2.-20"C,lh.62%,c)i.…     

Synthesis of (24R)-3β,5,14α-trihydroxy-5α-stigmast-7-en-6-one 3-benzoate

An ecdysteroid analog has been synthesized from -sitosterol.Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus', 220141, Belarus', Minsk, ul. Akad. Kuprevich, 5/2. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 488–491, July–August, 1999.     

NMR study on (1α, 2β, 4β, 5α, 7β)-7-[(hydroxydi-2-thienylacetyl) oxy]-9,9-dimethyl-3-oxa-9-azoniatricyclo [3.3.1.02,4] nonane bromide monohydrate

The structure of (1α, 2β, 4β, 5α, 7β)-7-[(hydroxydi-2-thienylacetyl) oxy]-9,9-dimethyl-3-oxa-9-azoniatricyclo [3.3.1.0^2,4] nonane bromide monohydrate was studied using 1D and 2D NMR techniques. Complete NMR assignments of the compound were obtained using DEPT, H–H COSY, as well as HMQC and HMBC heteronuclear correlation techniques.     

The synthesis of facial amphiphile 3α,7α-diaminocholestane

The facial amphiphile 3α,7α-diaminocholestane 3 was synthesized from 3β-acetoxy-7-ketocholestane 1 through a stepwise reductive amination. The reductive amination of 1 with NH₄OAc in the presence of NaBH₃CN, and protection with Boc₂O yielded 7α-(tert-butyloxycarbonyl)-aminocholestane 4 in 86% yield. The reductive amination of 6, which was obtained from 4 after hydrolysis and subsequent oxidation, with NH₄OT_f in the presence of NaBH(OEh)₃ provided 3 in 75% yield after protection with Boc₂O.     

Synthesis of new α,α,β,β-tetrafluoroesters

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.     

Reaction of 5β,6β-epoxy-16α,17α-cyclohexapregnane with methylmagnesium iodide

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.     

Zur Kobaltbestimmung mitβ-Nitroso-α-Naphthol

Zusammenfassung Die in der Literatur mitgeteilten Verfahren zur photometrischen Bestimmung des Kobalts mit-Nitroso--Naphthol wurden auf ihre Eignung für die Analyse von Mustern, die in der Landwirtschaft interessieren, einer Prüfung unterzogen. Dabei wurde gefunden, daß Störungen durch Platin, das aus den verwendeten Platingeräten stammt, sowie durch Mangan auftreten. Die Störung durch Mangan kann durch den Zusatz von Wasserstoffperoxyd eliminiert werden. Für die Ausschaltung des Einflusses durch Platin werden drei verschiedene Trennungsverfahren angegeben sowie ein photometrisches Näherungsverfahren für die Zwecke der Reihenanalyse.

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Summary The procedures given in the literature for the photometric determination of cobalt with-nitroso--naphthol were tested with regard to their suitability in the analysis of samples of interest to agriculturists. It was found that the platinum, arising from the platinum vessels employed, and also manganese interfere. The interference due to manganese can be eliminated by addition of hydrogen peroxide. Three different separating procedures are given to remove the effect of the platinum, as well as a photometric approximation procedure for the purposes of series analyses.

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Résumé Les techniques de dosage photométriques du cobalt à l'aide du-nitroso-naphtol, décrites dans la littérature ont été contrôlées quant à leur possibilité d'emploi dans l'analyse de modèles intéressant l'agriculture. Lors de cette étude il a été établi que la présence du platine provenant de l'emploi d'ustensiles de platine et celle du manganèse, provoquaient des perturbations. Les perturbations dues au manganèse peuvent être éliminées par l'addition d'eau oxygénée. Pour supprimer l'influence du platine les auteurs décrivent trois techniques de séparation et une technique photométrique d'approximation pour l'analyse de série.