Synthesis and molecular structure of 3β,28-diacetoxy-(20R)-lupan-29-oic acid

The methyl ester of 3β,28-diacetoxy-(20R)-lupan-29-oic acid was synthesized and its molecular structure was determined.     

Synthesis of (24R)-3β-hydroxystigmast-5-en-7-one

The natural compound (24R)-3-hydroxystigmast-5-en-7-one has been synthesized from -sitosterol.Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus', 220141, Belarus', Minsk. Ul. Akad. Kuprevicha, 5/2. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 484–487, July–August, 1999.     

Synthesis of diglycosides of 3β,20S-dihydroxydammar-24-en-12-one

The 3-O-β-D-galactopyranosyl-20-O-β-D-glucopyranoside and 3-O-β-D-glucopyranosyl-20-O-β-Dgalactopyranoside of 3β,20S-dihydroxydammar-24-en-12-one, which are structural analogs of chikusetsusaponin-LT₈ (1), a minor glycoside from Panax japonicus, were synthesized for the first time.     

Simple Synthesis of 17α,20β-Dihydroxypregn-4-en-3-one

Reduction of 17-hydroxyprogesterone (1) with NaBH ₄ produces 17,20-dihydroxypregn-4-en-3-one (2) and pregn-4-en-3,17,20-triol (3)     

Facile Synthesis of 6β-Hydroxy-7α(H)-eudesma-4-en-3-one and β-Cyperone

Eudesmane derivatives have been drawing considerable attention due to their wide spectrum of biological proerties, particulaly antifeedant, cell growth inhibitory and plant growth regulating activities.¹ In recent years a number of C-6 oxyfunctionalized eudesmanes and β-dihydroagarofurans,such as compounds 3-6,have been isolated from nature sources. However the reports on the synthesis of this particular kind of compounds are few and the reported syntheses are generally by synthetic methodology starting from α-santonin 2². Our interest of study on the synthesis of this kind of compounds prompted us to investigate a new synthetic route from cheap material (+)-dihydrocarvone 7.     

Synthesis of 19-hydroxypregn-4-en-20-one and 19-hydroxy-5β-pregn-3-en-20-one that selectively bind to membrane progesterone receptors,and assessment of their immunomodulatory effects

Russian Chemical Bulletin - A new approach to the synthesis of isomeric 19-hydroxypregn-4-en-20-one (1) and 19-hydroxy-5β-pregn-3-en-20-one (2), the selective ligands of membrane progesterone...     

Synthesis and Crystal Structure of a Novel 14,20-Annulated Pentacyclic Steroid 17(S)-Methyl-13β-hydroxyl-14(R),20(S)-epoxy-pregn-4-en-3-one

The title compound 17(S)-methyl-13β-hydroxyl-14(R),20(S)-epoxy-pregn-4-en-3-one was synthesized by an improved tandem reaction, and its structure was determined by IR, NMR, HR MS and X-ray single-crystal diffraction. The crystal belongs to orthorhombic, space group P212121 with a = 10.55248(15), b = 12.14700(16), c = 14.56841(18) ?, V = 1867.39(4) ?3, Z = 4, Dc= 1.175 g/cm3, μ= 0.604 mm-1, F(000) = 720, the final R = 0.0400 and w R = 0.1072 for 3610 observed reflections with I 2σ(I).     

A Facile Synthesis of 6β-Hydroxy-7α(H)-eudesma-4-en-3-one

Sesquiterpenesconstituteagroupofnaturalcompoundswhichexhibitconsiderablebiologicalactivities,suchasantiinflamatoryicytyotoxic'andcytotoxic',seedgendnation'andmolluscacidalactivities4.InrecentyearsanumberofC-6oxyfunctionalizedeudesmanesand6-dihydroagarofurans,suchascomPounds3-6',havebeenisolatedfromnaturesources.HoweverthereportSonthesynthesisofthisparticularkindofcompoundsarefewandthereportedsynthesesaregenerallybysyntheticmethodologystartingfroma-santonin2e.Ourinterestofstudyonthesynthesisof…     

Synthesis and studies of some cholest-5-en-3-ol-(3β)[4-phenylpyridylazo]carbonate-containing supramolecular hydrogen-bonded mesogens

Mesogenic materials containing cholest-5-en-3-ol-(3β)[4-phenylpyridylazo]carbonate (CPPC) and 4-n-alkyloxybenzoic acids have been synthesized using hydrogen bonding as a mechanism for self-assembly. Phase diagrams of the binary mixtures of the hydrogen bond donor and acceptor were established using polarizing optical microscopy. The maximum isotropization point was observed for the 50 mol % composition confirming the formation of stable 1 : 1 complexes due to intermolecular hydrogen bonding. All the supramolecular assemblies built from 1 : 1 molar ratios of the hydrogen bond donor and acceptor moieties exhibit well defined smectic A (SmA) liquid crystal phases on heating and cooling cycles. The SmA phases exhibited by the complexes are not observed for the individual components. The azobenzene moiety of CPPC undergoes trans-cis-photoisomerization with a quantum yield of 0.1 and the activation energy for the thermal cis-trans-isomerization was estimated as 92 kJ mol-¹.     

The structure of 16, 17β-epoxy-17α-pregn-5-en-3β-ol-20-one monohydrate

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.     

Autooxidation of Δ17(20)-20-hydroxy derivatives of steroids. Synthesis of 3β-acetoxy-17α-hydroperoxy-16α-methylpregn-5-en-20-one and its reduction to 17α-hydroxy derivative

An efficient procedure was proposed for the synthesis of 3β-acetoxy-17α-hydroperoxy-16α-methylpregn-5-en-20-one. Optimal conditions were found for the combined process including 1,4-addition of methylmagnesium bromide at the Δ¹⁶-20-oxo fragment of dehydropregnenolone acetate and autooxidation of resulting bromomagnesium 3β-acetoxy-16α-methylpregna-5,17(20)-dien-20-olate. The subsequent reduction of the 17α-hydroperoxy group and hydrolysis of the 3β-acetoxy group afforded 17α-hydroxy-16α-methyl-substituted dehydropregnenolone acetate and its 3-hydroxy analog in high yield.     

Stereoselective Synthesis of 3(R) and 3(S)-Hydroxyeicos-4(E)-en-1-yne, a Component of the Marine Sponge Cribrochalina Vasculum

Recently,aseriesofacetylenicalc0hols'possessingacharacteristic4-en-l-yn-3-olskeletonwasis0latedfromthemarinesp0ngeCribrochalinavasculum(Figure1)andshowedirnmnosuPpresiveandantitumoractivitiesinvitr0.1Toourknowledge,stereoselectivesynthesishasnotbeencarriedoutonthesecomPounds.WedescribehereinthestereoselectivesynthesisoftW0enantiomersof3-hydroxy-4(E)-en-l-yne(A)fromD-gluconolactoneandD-xyloserespectivelyusingacetylenictechnology.Bythepublishedmethod',theacetylenicalcohollwaspreparedfromD-gl…     

Synthesis of Hydroxylated Sterols(Ⅱ)--Synthesis of 24-Methylenecholest-4-en-3β,6α-diol

In our study on the soft coral,Alcyonium patagonicum,a new hydroxylated sterol,24-methylenecholest-4-en-3β,6α-diol(1) exhibiting a potent activity to murine leukemia cells(IC50=1 μg/mL) has been isolated[1] and synthesized[2,3].As a part of our studies on the relationship between the chemical structure and the biological activity of the hydroxylated sterols,the synthesis of 24-methylenecholest-4-en-3β,6α-diol(2) is reported here.     

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 3β-hydroxy-20-oxo-30-norlupan-28-oic (platanic) acid and its glycosides

All available literature data on the chemical synthesis and isolation from natural sources of 3β-hydroxy-20-oxo-30-norlupan-28-oic (platanic) acid and its derivatives and their biological activity were reviewed. A one-step synthesis of platanic acid from betulin was developed. Its glycosylation by α-acetobromoglucose (ABG) catalyzed by Ag₂O in various solvents such as pyridine, CH₂Cl₂, and their mixture was studied. The optimal synthetic schemes for platanic acid monoglucosides and diglucoside were found. NMR spectra of platanic acid and its glycosides were studied.     

Crystal and molecular structures of (3Z)-(±)-4-(2′-hydroxypropyl)amino-and (3Z)-4-(2′-hydroxyethyl)amino-pent-3-en-2-ones

An X-ray study of (3Z)-(±)-4-(2′-hydroxypropyl)amino-and (3Z)-4-(2′-hydroxyethyl)amino-pent-3-en-2-ones is reported. The bond lengths inside the H ring are equalized due to the classical N-H...O hydrogen bond between the carbonyl oxygen and the amino group. In the 4-(2′-hydroxyethyl)amino-pent-3-en-2-one crystal, due to the classical N-H...O bonds, infinite zigzag chains are formed along the 0b axis and arranged into a layered structure due to the weak C-H...O interactions. In (±)-4-(2′-hydroxypropyl)aminopent-3-en-2-one crystal, however, centrosymmetric dimers are formed, which are then linked by weak C-H...O intermolecular interactions to form a layered structure along the a0b plane.     

Synthesis and Structure of a Novel Macrocyclic Ligand( C_(22) H_(29) N_3 O_3 Br_2)

１　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｍａｉｎｔａｒｇｅｔｉｎｍａｃｒｏｃｙｃｌｉｃｄｅｓｉｇｎｉｓｔｏｓｙｎｔｈｅｓｉｚｅｍａｃｒｏｃｙｃｌｅｓｗｈｉｃｈａｒｅａｂｌｅｔｏｄｉｓｃｒｉｍｉｎａｔｅａｍｏｎｇｔｈｅｄｉｆｆｅｒｅｎｔｍｅｔａｌｃａｔｉｏｎｓ．Ｍａｎｙｆａｃｔｏｒｓｉｎｆｌｕｅｎｃｉｎｇｔｈｅｓｅｌｅｃｔｉｖｉｔｉｅｓｏｆｍａｃｒｏｃｙｃｌｅｓｆｏｒｃａｔｉｏｎｓｈａｖｅｂｅｅｎｄｅｔｅｒｍｉｎｅｄｓｕｃｈａｓｓｕｂｓｔｉｔｕｅｎｔｅｆｆｅｃｔ，ｄｏｎｏｒａｔｏｍｉｃｔｙｐｅｓａｎｄ…     

Synthesis and transformations of 2β,3β-diacetoxy-20-(4,5-dihydroisoxazol-5-yl)-6-oxo steroids

20-Hydroxy-20-(4,5-dihydroisoxazol-5-yl) steroid was brought into reactions typical of functionalization of rings A and B in ecdysteroids. The dihydroisoxazole ring remained unchanged in reactions leading to formation of the 2,3-dihydroxy-6-oxo moiety. The isomerization of 5-bromo derivative in acetic acid in the presence of a catalytic amount of hydrobromic acid and Lewis acids is accompanied by elimination of the hydroxy group from C²⁰ and subsequent migration of the double bond to the heteroring to afford the corresponding isoxazole derivative.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 10, 2004, pp. 1500–1505.Original Russian Text Copyright © 2004 by Litvinovskaya, Drach, Khripach.