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1.
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.  相似文献   

2.
文章描述了面包酵母将1, 4, 4α, 8α-四氢-1, 4-亚甲基萘-5, 8-二酮催化异构化为1, 4-二氢-5, 8-二羟基-1, 4-亚甲基萘, 而不是还原为相应的羟基化合物。  相似文献   

3.
Two novel analogues of triptolide were synthesized using triptolide as the starting material through reductive opening of epoxy ring, hydration and olefin epoxidation, and related ketones have also been afforded by oxidation of them with IBX or Jone‘s reagent.  相似文献   

4.
5.
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   

6.
Summary.  The stereoselectivities of the quaternization reactions of (4aα,8aβ,9aβ,10aα)- and (4aα,8aα,9aβ,10aα)-tetradecahydro-10-methylacridine with methyl- and ethyl iodide as well as those of (4aα,8aβ,9aβ,10aα)- and (4aα,8aα,9aβ,10aα)-10-ethyl-tetradecahydroacridine with methyl iodide were investigated using 13C NMR spectroscopy including 13C-labelling where appropriate. The methylations of both N-methyl amines occur by predominant (60% and 75%, respectively) equatorial approach, their ethylations occur sterospecifically by equatorial approach, and the methylations of the N-ethyl amines occur by highly stereoselective (> 90%) axial approach of the quaternizing reagent. Received October 27, 1999. Accepted November 22, 1999  相似文献   

7.
A theoretical study of prednisolone, 6-fluoroprednisolone, 9-fluoroprednisolone, and 6,9-difluoroprednisolone has been performed at the ab initio HF/6-31G, MP2/6-31G, and B3LYP/6-31G levels. Structural information and the electronic features of prednisolone and its derivatives and the synergistic effect of 6,9-difluoroprednisolone was examined. Contrary to the AM1 and MNDO results, we found 9-fluoroprednisolone is more stable than the 6-fluoroprednisolone. The increased corticosteroid activity of the 6,9-difluoroprednisolone is most likely due to electronic effects, mainly related to the receptor binding.  相似文献   

8.
Summary By the action of sodium in xylene on polychloro hydrocarbons containing -CCl2-CCl2- or- CC1=CC1-, groupings the corresponding symmetrical acetylenic hydrocarbons containing 10,14, and 18 carbon atoms in the molecule were obtained. From ,-disubstituted tetrachloroalkanes by the same method 1,10-diethoxy-5-decyne, 1,14-diethoxy-7-tetradecyne, and 1,14-bisdiethylamino-7-tetradecyne were obtained.The spectra were determined in the Optical Laboratory of the Institute of Heteroorganic Compounds of the USSR by N. A. Chumaevskii, who we thank.  相似文献   

9.
Ten α,α,α′-trisubstituted cyclododecanones were synthesized and characterized by elemental analyses, infrared, 1^H NMR and 13^C NMR spectra, and X-ray diffraction. NMR data could not give conformational information clearly, but some of their ring skeleton conformations of cyclododecanone moiety were showed to remain the unchanged [3333]-2-one conformation with little distortion, while the others were changed to the [3324]-2-one conformation in their crystal structures. These are consistent with the results of molecular mechanics calculation with Sybyl 6.9 software and Tripos force field, and semi-empirical quantum calculation with AM 1 method in Gaussian 98 software. Two geminal substituting groups are located at α-corner carbon atom, and the third group is at α-side-exo carbon atom in both conformations. Both [3333]-2-one and [3324]-2-one conformations are present in a dynamic equilibrium in the solution, but only one preferred conformation exists in the crystal solid.  相似文献   

10.
《Tetrahedron letters》1988,29(39):4943-4944
Subulacine N-oxide, a purportedly novel pyrrolizidine alkaloid from Heliotropium subulatum, was shown to have nmr and mass spectral properties identical with 1β,2β-epoxy-1α-hydroxymethyl-8α-pyrrolizidine, previously known from Crotalaria trifoliastrum.  相似文献   

11.
Stereoselective synthesis of d,l-,-dioxy-,-di-tert-butylglutaric acid hydroxyiminolactonitrile (3) was conducted by the reaction of dipivaloylmethane with HCN in ether. The corresponding hydroxylacetonitrile (4) and amide (5), acid (6), and its ester (7), from which dilactone (8) was synthesized with preparative yields, were obtained from3. Benzyl amide (9) was obtained by the reaction of8 with BnNH2. The iminolactone structure3 of dipivaloylmethane bis-cyanohyrin, thecis-pseudo-a orientation of the functional substituents in3–7 and9, and the structure of the dilactone8 were confirmed by the1H,13C NMR,IR and mass spectra.For previous communication, see [2].N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1591–1601, July, 1992.  相似文献   

12.
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.
By reactions of ,-diamines with 1,2-dihaloethanes there were synthesized ,-bis-N-aziridinoalkanes (la-g) and bis-N-aziridinoethyl ether (II). From 1,3-diaminopropane and dichloroethane bis-aziridine (III) was isolated in addition to (Ia). NMR spectra of the products were studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 882–885, April, 1991.  相似文献   

15.
16.
利用小分子meso-四(α,α,α,α-O-苯乙酰苯)卟啉作为全抗原免疫小鼠,通过细胞融合等技术制备了单克隆抗体(McAb)1F2,利用高效液相色谱(HPLC)、基质辅助激光解吸飞行时间质谱(MALDI/TOFMS)证明纯化得到的单抗是很纯的.McAb1F2的保留时间是2.63 min,亚型为IgG2a,相对分子量为156 678.8.McAb 1F2-卟啉复合物形成时,卟啉Soret带最大吸收峰从408nm红移到416nm,并有增色效应,说明McAb1F2-卟啉是刚性且紧密结合.抗体酶稳定性很高,但比活力只有4.687 5 U/mg,为天然酶HRP的1.899%.抗体酶的Km=20.29 mmol/L,kcat=396.82 min-1,kcat/Km=1.955 7×104L·mol-1·min-1.  相似文献   

17.
The title compound 3a-hydroxy-3-phenyl-1,2,3,3a,8a-pentahydrocyclopenta[α]inden-8-one 2 (C18H16O2, Mr = 264.31) has been obtained by the treatment of 2-(3-iodopropyl)-2phenylindan-1,3-dione 1 with tributyltin hydride in refluxing benzene, and its crystal structure was determined by single-crystal X-ray diffraction. The analysis was carried out by direct and Fourier methods and the structure was refined by full-matrix least-squares computations. The title compound crystallizes in monoclinic, space group P21/n with a = 9.947(3), b = 10.336(3), c = 13.239(4) (A), β = 95.565(6)o, V = 1354.7(7) (A)3, Z = 4, Dc = 1.296 g/cm3, μ(MoKα) = 0.083 mm-1, F(000) = 560, the final R = 0.0749 and wR = 0.1191. X-ray analysis revealed that the bond length of O(2)C(12) is 1.219(2) (A), slightly longer than that of the normal C=O bond (1.119 (A)). The dihedral angle between planes II and III is almost 180°, while plane II is almost vertical to plane I consisting of C(1), C(3), C(4) and C(5) with the deviation of C(2) being 0.6269 (A). In addition, there exist intermolecular hydrogen bonds between O(2) and H(1)-O(1) in the crystal structure.  相似文献   

18.
1 INTRODUCTION Many organic substances of interest contain vari-ous types of rings and it becomes important to ex-plore and develop new approaches to appropriatelyfunctionalize medium and large rings. Free radicalcyclization reaction is a new strategy to constructdifferent types of cyclic compounds including biolo-gically active natural products and pharmaceuti-cals[1~4], and nowadays it is one of the importantresearch fields of organic chemistry. Up to date, noreport on the radical cycl…  相似文献   

19.
Ohne ZusammenfassungMit 1 Abbildung.  相似文献   

20.
四氟乙烯与甲醇在游离基引发剂的作用下发生調节聚合反应,生成一系列的低級調聚产物,即含有奇数碳原子的α,α,ω三氫全氟醇类: nC_2F_4+CH_3OH→H(CF_2—CF_2)_nCH_2OH(n=1—12)这些产物具有多氟化合物特有的稳定性和不燃性,又含有活泼的伯醇基,所以是氟有机化学中的一类重要合成中間体,又是制备某些特殊材料如高溫潤滑剂、介  相似文献   

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