Ab Initio Study of Prednisolone, 6α-Fluoroprednisolone, 9α-Fluoroprednisolone,and 6α,9α-Difluoroprednisolone

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.     

Oxidative Coupling of 4α,9-Diaza-1,2,4α,9α-tetrahydrofluorenes. 5. Reaction with o-Aminophenol and o-Aminothiophenol

Oxidative coupling of 4,9-diaza-1,2,4,9-tetrahydro-9H-fluorenes with o-aminophenol and o-aminothiophenol in the presence of MnO₂ gives o-hydroxyphenyl- and o-mercaptophenylquinonediimines, cyclization of which gives derivatives of phenoxazine and phenothiazine.     

9-α-carbethoxy(carboxy)alkyl-4-azafluorenes

9-Carbethoxymethyl- and 9-(-carbethoxyethyl)-4-azafluorenes were obtained by the reduction of 9-chloro-9--carbethoxyalkyl-4-azafluorenes, and the corresponding acids were obtained from them. Some information regarding the transformations of 9-hydroxy-9--carboxyethyl-4-azafluorene under the influence of polyphosphoric acid (PPA) with heating was obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1083–1085, August, 1992.     

A taxane with a novel 9α,13α-oxygen bridge from Taxus cuspidata needles

A novel taxane with an unprecedented hemiacetal ring between C-13 and C-9 was isolated from the needles of Taxus cuspidata. The structure was characterized as (12αH)-2α,10β-diacetoxy-5α-cinnamoyloxy-9α,13α-epoxytax-4(20)-ene-11β,13β-diol (1). This is the first example of a natural taxane with a C-13 and C-9 oxygen bridge to form an unusual 6/8/6/6-membered ring system.     

Access to new sequiterpenoids by catalytic acid rearrangement of 9α-hydroxyparthenolide

The catalytic acid rearrangement of 9α-hydroxyparthenolide (1), the main constituent of Anvillea radiata, has been studied. Several new sesquiterpene compounds were obtained and their structures were fully elucidated. A mechanism to explain the formation of these compounds is proposed.     

Transformation of 5α-H-pregn-16-en-3β-ol-20-one into pregn-4-ene-9α,16α,17α-triol-3,20-dione 16,17-acetonide

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.     

Reaction of 9-amino(phenylamino)methylene- and 9-α-aminobenzylidene-4-azafluorenes with some electrophilic reagents

It was shown that initial protonation of 9-aminomethylene-4-azafluorene takes place at the pyridine nitrogen atom. In nitrosation of this azafluorene, 4-azafluorenone oxime is formed, and in reaction with dichlorocarbene, 1-amino-2, 2'-dichlorospiro[4-azafluorene-9,3-cyclopropane] is formed. Acylation yields mono- or diacyl derivatives as a function of the acylating agent and reaction conditions.Russian University of National Friendship, Moscow 117923. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 527–533, April, 1995. March 14, 1995.     

三缺位杂多阴离子α-A-PW9O9-34的苯基硅衍生物的合成和晶体结构

合成了三缺位杂多阴离子的苯基硅衍生物(TBA)3[α-A-PW9O34(PhSiO)3(PhSi)]*2H2O(记为1, TBA为四丁基铵阳离子), 并由元素分析、红外光谱、紫外光谱对化合物进行了表征, 研究了化合物的热性质. 结构分析结果表明, 该化合物属三方晶系, 空间群R3, 晶胞参数a=1.416 96(16) nm, b=1.421 63(16) nm , c=1.416 61(16) nm, α=99.801(17)°, β=99.843(17)°, γ=99.844(17)°, V=2.711 1(5) nm3. Z=1, R=0.054 8. 该化合物的阴离子是由1个α-A-PW9单元, 通过6个W-O-Si桥键与3个PhSiO单元相连, 3个PhSiO又通过Si-O-Si桥键与另1个处于帽位的PhSi相连, 形成饱和闭合笼形结构.     

9-α-Nitro(hydroxy,amino)benzylidene- and 9-Hydroxy(amino)methylene-4-azafluorenes

Nitration of 9-benzylidene-4-azafluorene with acetyl nitrate leads to the formation of its 9--nitrobenzylidene derivative; reduction of the latter gives the corresponding enamine and oxime. Reaction of 4-azafluorene with ethyl benzoate and ethyl formate gives the hydroxybenzylidene and hydroxymethylene derivatives, which upon condensation with amines generate the corresponding enamines. Reduction of 9-formylazafluorene oxime gives 9-aminomethyleneazafluorene. All of the newly synthesized compounds were isolated in the form of mixtures of their Z- and E-isomers, and their structures were established using PMR spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 212–217, February, 1991.     

三缺位α-9钨镓杂多酸盐的合成与性质

本文报道了一种新的三缺位杂多阴离子α-[GaW_9O_(34)H_2]~(9-)的钠、钾、四甲基铵盐的合成方法,并通过元素分析、红外、紫外、极谱、热分析等方法对它进行了表征。α-[GaW_9-O_(34)H_2]~(9-)是一具有三个空位的杂多阴离子,它能与过渡金属离子反应生成具有Keggin结构的三取代钨镓杂多阴离子[GaW_9O_(37)M_3(H_2O)_3]~(R-)。     

Synthesis and reduction of 9-(α-nitrophenacylidene)-4-azafluorene

Reaction of 9-phenacylidene-4-azafluorene with acetyl nitrate produces a mixture of geometric isomers of 9-(-nitrophenacylidene)-4-azafluorene. The nitro group splits off upon reduction of the product in the system zinc-ammonia and zinc-acetic acid and on Raney nickel. Proceeding of the Henry retro-reaction has been pointed out.Russian Peoples' Friendship University, Moscow 117918, RussiaTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 342–347, March, 1999.     

Synthesis and reactions of 9-hydroxy-(α-alkoxycarbonylalkyl)-4-azafluorenes

The Reformatsky reaction with 4-azafluorenone has given 9-hydroxy-9-(-alkoxycarbonylalkyl)-4-azafluorenes. The course of this reaction with respect to the -haloester used, and the conversion of these hydroxyesters into hydroxy- and ,-unsaturated acids have been examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 81–85, January, 1991.     

New variants in the total synthesis of 14β-hydroxy-17α,R-8α,9β-estradiol derivatives

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.     

Synthesis of (+)-drim-9(11)-en-8α-ol from sclareol

A drimane-type sesquiterpenoid, (+)-drim-9(11)-en-8-ol, was synthesized from sclareol in four steps. The ozonolysis product of sclareol diacetate reacts with Cu(OAc)₂·H₂O to give 8-acetoxy-14,15-bisnorlabdan-13-one. Photolysis of this compound followed by alkaline hydrolysis results in the target compound belonging to the normal steric series. (+)-Drim-9(11)-en-8-ol acetate is highly unstable and decomposes during chromatography on SiO₂.     

Synthetic Studies toward C3‐C9 Segment of Soraphen A1α

The ring‐closure metathesis of the diene (2S,3R,4S)‐1‐(tert‐butyldiphenylsilyloxy)‐2,4‐dimethylhex‐5‐en‐3‐yl acrylate produced the dihydropyrone with the correct stereochemistry for Soraphen A_1α synthesis. The C2,C3 stereocenters were introduced by the addition of the (Z)‐crotyl‐n‐butylstannane to the β‐alkoxyaldehyde(S)‐3‐(benzyloxy)‐2‐methylpropanal in presence of TiCl₄ as a chelating catalyst to give the desired anti,syn homoallyic alcohol (2S,3R,4S)‐1‐(tert‐butyldiphenylsilyloxy)‐2,4‐dimethylhex‐5‐en‐3‐ol.     

Synthesis of (22E,24R)-ergosta-4,7-22-triene-3,6-dione and its 14α-hydroxy- and 9α,14α-dihydroxy derivatives

^4,7-3,6-Diketosteroids have been synthesized from ergosterol (1).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. 354–358, May–June, 1999.     

新型荧光试剂N-9-吖啶-α-氨基酸的合成及表征

新型荧光试剂N-9-吖啶-α-氨基酸的合成及表征;荧光试剂; N-吖啶-α-氨基酸; 合成;表征     

三缺位杂多阴离子α—A—PW9O34^9—的苯基硅衍生物的合成和晶体结构

合成了三缺位杂多阴离子的苯基硅衍生物 (TBA) 3[α-A-PW9O34 (Ph Si O) 3(Ph Si) ]· 2 H2 O(记为 1 ,TBA为四丁基铵阳离子 ) ,并由元素分析、红外光谱、紫外光谱对化合物进行了表征 ,研究了化合物的热性质 .结构分析结果表明 ,该化合物属三方晶系 ,空间群 R3,晶胞参数 a=1 .41 696(1 6) nm,b=1 .42 1 63 (1 6)nm,c=1 .41 661 (1 6) nm,α=99.80 1 (1 7)°,β=99.843 (1 7)°,γ=99.844(1 7)°,V=2 .71 1 1 (5 ) nm3.Z=1 ,R=0 .0 5 48.该化合物的阴离子是由 1个α-A-PW9单元 ,通过 6个 W— O— Si桥键与 3个 Ph Si O单元相连 ,3个 Ph Si O又通过 Si— O— Si桥键与另 1个处于帽位的 Ph Si相连 ,形成饱和闭合笼形结构     

新型氧离子导体La2Mo1．9Al0．1O9-α陶瓷的合成及电性能

通过高温固相法合成了La2Mo1.9Al0.1O9-a陶瓷样品.XRD测试结果表明,该样品为一立方相结构,Al3 离子在Mo6 位置的固溶摩尔浓度为5%时能完全抑制La2Mo2O9的相变.采用交流阻抗谱、氧浓差电池、氧泵等电化学方法系统地研究了该陶瓷样品在600～1000℃下的离了导电特性.结果表明,氧浓差电池电动势的实测值与理论值吻合得很好,离子迁移数为1,表明该陶瓷样品在该温度下氧气气氛中为一纯离子导体;氧浓差电池放电及氧的电化学透过(氧泵)实验结果进一步证实了该样品在氧气气氛中为一纯氧离子导体;1000℃时其氧离子电导率达到了0.12 S·cm-1,明显高于相同条件下母体及La2Mo1.9Ga0.1O9-a的氧离子电导率.