Synthesis of 3β,6α-dihydroxy-5α-cholan-23-one

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).     

Stereoselective Synthesis of [2S,3R]-β-Hydroxy Ornithine

(2S,3R)-threo-β-hydroxy ornithine has been synthesized in a stereoselective manner by the C₂ opening of epoxyalcohol 9 with benzyl isocyanate.

     

Synthesis of (22R, 25R)-3β,26-Dihydroxy-5α-furostan-6-one #

The synthesis of a plant growth promoter furostanol which bears the characteristic functionality of teasterone on rings A and B is described.

     

Novel Synthesis of 2β,3β,20β-Triacetoxy-5 -pregnan-6-one

Pregnenolone (2) is used in a novel synthesis of 2,3,20-triacetoxy-6-ketosteroid (6), a key intermediate in the preparation of 20-hydroxyecdysone (1)     

Synthesis and Structure of 6'-Diethylamino-2'-phenacylami nospiro-[isobenzofuran- 1 (3H), 9'- [9H]xanthen]-3-one

1mTRODUCTIONWehavereportedsomenuorancomPoundswithdifferentsubstitutedgroups"~'>.Thispaperdescribesacontinuationofourinvestigationonthenuoranderivatives.ThecrystalstructureofthecomPOundC,zHzsNzo'(I)(whereRl-NEt2,R2=H,R3=NHCHzCoCeHs,R`=H)wasdeterminedbyX-raydiffractionmethod.Inaddition,wealsocomparethetitlecomPOundwithotherfluorancomPounds.2EXPERIMENTAL2.1SynthesisAmixtureof2'-carboxy-4-diethylamino-2-hydrzophenoneandP-hydroxy-acetanilide(molarratio1:l)insulfuricacidwasheated…     

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.     

Synthesis of 6-chloronicotinates of steroidal 3β,5α,6β-triols and 3β,5-dihydroxy-6-ketones

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.     

Unusual oxidation reactions of 7α-methyl- and 7α-phenylcholest-5-ene-3β,7β-diol

Summary Ozonation of 7-methyl (or 7-phenyl) cholest-5-ene-3,7-diol 3-TBDMS ether afforded the corresponding 5,6-epoxy derivatives. The same product was formed byMCPBA oxidation. The reaction of 7-phenylcholest-5-ene-3,7-diol with CrO₃ yielded 3,7-dioxo-6,7-seco-7-phenylcholest-4-ene-5-carboxaldehyde. An analogous B-seco aldehyde was obtained from 7-methylcholest-5-ene-3,7-diol in addition to 7-methylcholesta-4,6-dien-3-one.Jones oxidation of 7-phenylcholest-5-ene-3,7-diol or B-seco-aldehyde gave 3,7-dioxo-6,7-seco-7-phenylcholest-4-en-6-oic acid isolated as its methyl ester upon treatment with diazomethane.

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Ungewöhnliche Oxidation von 7-Methyl- und 7-Phenylcholest-3-en-3,7-diol

Zusammenfassung Ozonolyse von 7-Methyl- bzw. 7-Phenyl-cholest-3-en-3,7-diol-3-TBDMS-ether ergab die entsprechenden 5,6-Epoxy-Derivate.MCPBA-Oxidation führte zum gleichen Ergebnis. Bei der Reaktion von 7-Phenyl-cholest-5-en-3,7-diol mit CrO₃ wurde 3,7-Dioxo-6,7-seco-7-phenyl-cholest-4-en-5-carbaldehyd gebildet. Einen analogen B-seco-Aldehyd erhält man neben 7-Methyl-cholesta-4,6-dien-3-on auch aus 7-Methyl-cholest-5-en-3,7-diol. DurchJones-Oxidation von 7-Phenyl-cholest-5-en-3,7-diol oder B-seco-Aldehyd erhält man 3,7-Dioxo-6,7-seco-7-phenylcholest-4-en-6-carbonsäure, die nach Behandlung mit Diazomethan als ihr Methylester isoliert wurde.

     

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.     

Total synthesis and properties of prostaglandins 30. Modification of (1S,5R)-2-oxabicyclo[3.3.0]-6-octen-3-one at the α-carbon atom

Derivatives of -alkyl-, -alkylidene-, and -hydroxymethylene-2-oxabicyclo[3.3.0]-6-octen-3-one were obtained. The possibility of functional substitution of the bicyclic -lactones at the position to the carbonyl group was thereby demonstrated.For Communication 29, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1621–1630, December, 1991.     

Synthesis and structural studies of (1R,2R,5R)-chloro{o-[β-(2-hydroxy-2,6,6-trimethylbicyclo[3.1.1]hept-3-ylidenamino)ethyliminomethyl]phenoxy-O,N,N}palladium(II)

The reaction of (1R,2R,5R)-3-[{2-[(2-hydroxybenzylidene)amino]ethyl}imino]-2,6,6-trimethylbicyclo[3.1.1]heptan-2-ol with lithium tetrachloropalladate was studied. A chiral palladium(II) complex was thus obtained and its structure was confirmed by NMR spectroscopy and X-ray diffraction analysis.     

α-Fluorination of 6-phenylsulfinyl-2-azabicyclo[2.2.1]heptan-3-one and synthesis of 2′-fluoro substituted carbovir

Fluorination of phenylsulfinyl bicycloamide using molecular fluorine proceeded preferentially with inversion of the carbon atom having the sulfinyl group to afford α-fluorinated sulfonyl bicycloamide in fair yield. The fluorinated sulfonyl bicycloamide was converted to 2′-fluoro substituted carbovir via reductive desulfonylchlorination.     

Bi3GaS5]2[Ga3Cl10]2[GaCl4]2·S8 containing heterocubane-type [Bi3GaS5]2+, star-shaped [Ga3Cl10]-, monomeric [GaCl4]- and crown-like S8

By reaction of elemental bismuth, sulfur, bismuth(III) chloride and gallium(III) chloride in the ionic liquid (BMIm)Cl (BMIm: 1-butyl-3-methylimidazolium), [Bi(3)GaS(5)](2)[Ga(3)Cl(10)](2)[GaCl(4)](2)·S(8) is obtained as red transparent crystals. According to X-ray structure analysis based on single crystals, the title compound crystallizes with triclinic lattice symmetry and is composed of heterocubane-type [Bi(3)GaS(5)](2+) cations, trimeric star-shaped [Ga(3)Cl(10)](-) anions with three (GaCl(4)) tetrahedra sharing a single central chlorine atom, monomeric [GaCl(4)](-) tetrahedra and neutral, crown-shaped S(8)-rings. Here, the heterocubane [Bi(3)GaS(5)](2+) as well as the star-shaped [Ga(3)Cl(10)](-) are observed as building units for the first time. [Bi(3)GaS(5)](2)[Ga(3)Cl(10)](2)[GaCl(4)](2)·S(8) is further characterized by X-ray powder diffraction as well as by thermogravimetry/differential thermal analysis.     

Catalytic decomposition of branched α'-phenoxy-α-iazo ketones affording 2, 8h-cyclohepta[b]furan-3-one and 2h-cyclohepta[b]furan-3a(3ah)methyl-3-one

The decomposition induced by bis(hexafluoroacetoacetonato)Cu II on branched α-diazo ketones 1 bearing a phenoxy group at the α'-carbon has been investigated. The course of the reactions has been shown to be dependent upon substitution. Mixtures of furanones 2 and chromanones 4 were obtained from α-unsubstituted substrates 1b–d, as in the case of 1a. Instead, among the α-mono substituted substrates 1f and 1g selectively gave cycloneptatrienes 3f and 3g, respectively, while 1e and 1h gave mixtures of the corresponding 3 and 4. Cycloheptatrienes 3 easily rearranged to chromanones 4. The intermediacy of norcaradienes 5 has been tentatively proposed in the catalytic decomposition of 1, and in rearrangement of 3e–h to 4e–h.     

Synthesis and Crystal Structure of Spiro[1-bromo(S)-4-(R)-hydroxy-5-oxa-6-oxo-bicyclo[3.1.0]hexane-2,2''''-(3''''-diethyl-α-(S)-4''''''''-Cl-benzyloxyphosphonyl-4''''-(1R,2S,5R)-menthyloxybutyrolactone)]

1 INTRODUCTION In recent years, phosphorus compounds havebeen playing an important role in the new “high-tech” areas including life science and industrial te-chnology[1, .At the same time, the asymmetric syn- 2]thesis of various natural compounds containing cyc-lopropane components and organophosphorus grouphas attracted much attention due to their special bio-logical functions and antibiological activities[3～5].Despite the great advances in these areas, no novelapproach to the efficien…     

Reaction of 3β-chloro-5α,6α-epoxysteroids with trifluoroacetic acid

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.     

Photochemical formation and decomposition of 8-[β-arylethenyl]-2,2,6-trimethyl-7,9,10-trioxa-tricyclo[6.2.2.0]dodec-11-ene to novel 6-hydroxy-1,7,7-trimethyl-2-oxa-bicyclo[4.4.0]dec-4-en-3-one in the presence of oxygen

Irradiation of (E,E)-arylidene-β-ionones in the presence of oxygen leads to the formation of 8-[β-arylethenyl]-2,2,6-trimethyl-7,9,10-trioxa-tricyclo[6.2.2.0^1,6]dodec-11-enes (3). However, prolonged irradiation in the presence of oxygen leads to their conversion to 6-hydroxy-1,7,7-trimethyl-2-oxa-bicyclo[4.4.0]dec-4-en-3-one (4), apparently proceeding through addition of oxygen to the side chain π-bond in 3.     

Isolation and Crystal Structure of 4β,6α,9α- Trimethy-2-carboxyltricyclo[6.3.0.0^（4,5）]undec-2-ene

The title compound, 4β,6α,9α-trimethy-2-carboxyltricyclo[6.3.0.0^（4,5）]undec-2-ene, is a sesquiterpene which was first isolated from Ligularia caloxantha and characterized by MS and NMR. In addition, the structure was determined by X-ray single-crystal diffraction. It crystallizes in orthorhombie, space group P212121 with a = 8.197（2）, b = 14.876（3）, c = 22.281（6） A, α = β = γ = 90°, V = 2716.9（11） ]A^3, Z = 8, C15H22O2, Mr = 234.34, Dc = 1.146 g/cm^3, μ（MoKa） = 0.074 mm^-1, F（000） = 1024, the final R = 0.0384 and wR = 0.0856 for 6200 independent reflections （Rint = 0.066） and 2538 observed ones （I 〉 2σ（I））. In the molecule, there are three fused five-membered rings; while in this crystal form, the asymmetric unit contains two molecules of the same hand and they are linked together by two intermolecular O-H...O hydrogen bonds to form a dimer.