Synthesis of (2<Emphasis Type="Italic">S</Emphasis>,3<Emphasis Type="Italic">S</Emphasis>,4<Emphasis Type="Italic">S</Emphasis>)-2,3-<Emphasis Type="Italic">O</Emphasis>-isopropylidene-4-(methoxycarbonylmethyl)cyclopentan-1-one

(2S,3S,4S)-2,3-O-Isopropylidene-4-(methoxycarbonylmethyl)cyclopentan-1-one was synthesized starting from D-ribose through methyl (Z)-3-(5-acetyl-2,2-acetoxyacetyl-2,2-dimethyl-1,3-dioxolan-4-yl)prop-2-enoate which was subjected to cyclization in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, followed by decarboxylation.     

Oxidation of (1<Emphasis Type="Italic">S</Emphasis>,5<Emphasis Type="Italic">R</Emphasis>,7<Emphasis Type="Italic">R,S</Emphasis>)-(4,7-dimethyl-6-oxabicyclo[3.2.1]oct-3-en-7-yl) methanol with pyridinium chlorochromate

The oxidation of (1S,5R,7R,S)-(4,7-dimethyl-6-oxabicyclo[3.2.1]oct-3-en-7-yl)methanol epimeric at the C⁷ atom resulted in scalemic (5R)-5-acetyl-2-methylcyclohex-2-en-1-one.     

Asymmetric hydrogen-transfer hydrogenation on rhodium(I) complexes with new optically active salen ligands derived from (4<Emphasis Type="Italic">S</Emphasis>,5<Emphasis Type="Italic">S</Emphasis>)-4,5-bis(aminomethyl)-2,2-dimethyl-1,3-dioxolane

New optically active C ₂-symmetric salen-type ligands were synthesized on the basis of (4S,5S)-4,5-bis(aminomethyl)-2,2-dimethyl-1,3-dioxolane. These ligands were used to obtain cationic (trifluoromethanesulfonate) and neutral (chloride) rhodium(I) complexes with [(4S,5S)-2,2-dimethyl-5-{[(E)-pyridin-2-ylmethylidene]aminomethyl}-1,3-dioxolan-4-yl]-N-[(E)-pyridin-2-ylmethylidene]methanamine and [2,2-dimethyl-5-{[(E)-quinolin-2-ylmethylidene]aminomethyl}-1,3-dioxolan-4-yl]-N-[(E)-quinolin-2-ylmethylidene] methanamine. The latter complex ensured preparation of (S)-2-phenylethanol with an optical yield of 34.8% by transfer hydrogenation of acetophenone.     

Cyclopropanation of methyl (2<Emphasis Type="Italic">E</Emphasis>)-3-[(1<Emphasis Type="Italic">R</Emphasis>,6<Emphasis Type="Italic">S</Emphasis>)-7,7-dimethyl-2-oxo-3-oxabicyclo[4.1.0]hept-4-en-4-yl]prop-2-enoate with dichlorocarbene and diazomethane

Cyclopropanation of methyl (2E)-3-[(1R,6S)-7,7-dimethyl-2-oxo-3-oxabicyclo[4.1.0]hept-4-en-4-yl]prop-2-enoate with dichlorocarbene occurred at the endocyclic double bond, while its reaction with diazomethane in the presence of Pd(acac)₂ involved the exocyclic double bond. The resulting lactones reacted with sodium methoxide in methanol via opening of one cyclopropane fragment.     

Crystallographic study and molecular modeling on the oxidation product of <Emphasis Type="Italic">N</Emphasis>-[(8<Emphasis Type="Italic">R</Emphasis>)-2-methoxy-5,6,7,8,9,10-hexahydro-6,9-methanocyclohepta[<Emphasis Type="Italic">b</Emphasis>]indol-8-yl]acetamide

Crystallization of N-[(8R)-2-methoxy-5,6,7,8,9,10-hexahydro-6,9-methanocyclohepta[b]indol-8-yl]acetamide was accompanied by oxidation at the C^5a–C^10a bond with formation of N-[(5S)-10-methoxy-2,8-dioxo-1,2,3,4,5,6,7,8-octahydro-3,6-methano-1-benzazecin-5-yl]acetamide whose structure was determined by X-ray analysis. Docking of this compound into melatonin-binding pocket of MT_1A receptor was simulated by computer-assisted molecular modeling.     

Synthesis of <Emphasis Type="Italic">ortho</Emphasis>-carboranyl derivatives of (<Emphasis Type="Italic">S</Emphasis>)-asparagine and (<Emphasis Type="Italic">S</Emphasis>)-glutamine

(S)-Asparagine and (S)-glutamine ortho-carboranyl derivatives with free amino and carboxy groups in the α-position were synthesized. By an example of N ^γ-(1,2-dicarba-closo-dodecarboran-3-yl)-(S)-glutamine it was demonstrated that the developed synthetic approach carboranyl derivatives of amino acids allowed the preparation of optically pure isomers.     

Structures and photochromic properties of fulgides based on naphtho[1,2-<Emphasis Type="Italic">b</Emphasis>]furan and benzo[<Emphasis Type="Italic">g</Emphasis>]indole

The novel heterocyclic fulgides, i.e. 3-isopropylidene-4-{1-[5-methoxy-1-(4-methoxy-phenyl)-2-methyl-1H-benzo[g]indol-3-yl]ethylidene}dihydrofuran-2,5-dione and 3-isopropylidene-4-[1-(1-benzyl-5-methoxy-2-methyl-1H-benzo[g]indol-3-yl)ethylidene]dihydrofuran-2,5-dione, were prepared and isolated as E-isomers. Photochromism, E-configuration, and high resistance to photocoloration—photobleaching of solutions of these fulgides as well as 3-isopropylidene-4-[1-(5-methoxy-2-methylnaphtho[1,2-b]furan-3-yl)ethylidene]dihydro-furan-2,5-dione and 3-isopropylidene-4-[1-(5-methoxy-2-methyl-1-phenyl-1H-benzo[g]indol-3-yl)ethylidene]dihydrofuran-2,5-dione synthesized previously were shown by X-ray diffraction analysis, ¹H NMR spectroscopy and electronic absorption spectroscopy. The novel fulgides show fluorescence and high thermal stability of photogenerated cyclic form. Repeated photo-coloration—photobleaching is accompanied by reversible photoinduced E—Z isomerization. Benzo[g]indolyl fulgides are characterized by the longer wavelength absorption of both original (E) and photoisomeric cyclic (C) forms as compared to naphthofuran fulgide.     

Hydrogenation and conformational analysis of (1<Emphasis Type="Italic">R</Emphasis>,2<Emphasis Type="Italic">R</Emphasis>,6<Emphasis Type="Italic">S</Emphasis>)-3-methyl-6-(1-methylethenyl)cyclohex-3-ene-1,2-diol

Hydrogenation of (1R,2R,6S)-3-methyl-6-(1-methylethenyl)cyclohex-3-ene-1,2-diol was studied. Nickel chloride-sodium tetrahydridoborate system turned out to selectively reduce the double bond in the isopropenyl group. The results of conformational analysis of (1R,2R,6S)-3-methyl-6-(1-methylethenyl)cyclohex-3-ene-1,2-diol and its partly and completely hydrogenated derivatives were in a good agreement with the NMR data.     

Synthesis and structures of benzo[<Emphasis Type="Italic">cd</Emphasis>]furo[2,3-<Emphasis Type="Italic">f</Emphasis>]indol-4(5<Emphasis Type="Italic">H</Emphasis>)-one derivatives

A procedure was developed for the synthesis of derivatives of the new heterocyclic system, benzo[cd]furo[2,3-f]indole, based on the cyclodehydration of 6-acylmethyloxy-1-alkyl-benzo[cd]indol-2(1H)-ones. Either 7- or 8-aryl derivatives of benzo[cd]furo[2,3-f]indol-4(5H)-ones can be prepared depending on the reaction conditions. The molecular and crystal structures of 7- and 8-phenylbenzo[cd]furo[2,3-f]indol-4(5H)-ones were established by X-ray diffraction.     

Synthesis of isomeric 2-oxazolidinones from (1<Emphasis Type="Italic">R</Emphasis>,2<Emphasis Type="Italic">R</Emphasis>)-and (1<Emphasis Type="Italic">S</Emphasis>,2<Emphasis Type="Italic">S</Emphasis>)-2-amino-1-(4-nitrophenyl)-1,3-propanediols

A synthesis is reported for (4R,5R)-and (4S,5S)-4-hydroxymethyl-5-(4-nitrophenyl)oxazolidin-2-ones and (1′R,4R)-and (1′S,4S)-4-[hydroxy(4-nitrophenyl)methyl]oxazolidin-2-ones from (1R,2R)-and (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediols. The effect of the experimental conditions on the formation of these compounds was studied. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1562–1570, October, 2007.     

Crystal structure investigation of (4<Emphasis Type="Italic">S</Emphasis>,5<Emphasis Type="Italic">S</Emphasis>)-4-[(dichloroacetoxy)methyl]-5-(4-nitrophenyl)-2-oxazolidinone

The structure of (4S,5S)-4-[(dichloroacetoxy)methyl]-5-(4-nitrophenyl)-2-oxazolidinone has been determined by crystal structure investigation.     

Halocyclization of 2-(2-{4-[allylamino(thioxo)methyl]piperazin-1-yl}ethyl)-1<Emphasis Type="Italic">H</Emphasis>-benzo[<Emphasis Type="Italic">de</Emphasis>]isoquinoline-1,3(2<Emphasis Type="Italic">H</Emphasis>)-dione

Cyclization of 2-(2-{4-[allylamino(thioxo)methyl]piperazin-1-yl}ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione by the action of iodine, bromine, or sulfuryl chloride gave 2-(2-{4-[4,5-dihydro-5-(halomethyl)-thiazol-2-yl]piperazin-1-yl}ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione hydrohalides which were converted into 2-{2-[4-(5-methylthiazol-2-yl)piperazin-1-yl]ethyl}-1H-benzo[de]isoquinoline-1,3(2H)-dione.     

Synthesis of (<Emphasis Type="Italic">S</Emphasis>)-(+)-6-aryl-3-acetyl-6-trifluoromethyl-5,6-dihydropyridin-2(1<Emphasis Type="Italic">H</Emphasis>)-ones

(S)-(+)-4-Amino-4-aryl-5,5,5-trifluoropentan-2-ones reacted with ethyl acetoacetate and ethyl trifluoroacetoacetate to give (S)-(+)-6-aryl-3-acetyl(or trifluoroacetyl)-6-trifluoromethyl-5,6-dihydropyridin-2(1H)-ones.     

Molecular structure of (4Z)-{[(1<Emphasis Type="Italic">R</Emphasis>,6<Emphasis Type="Italic">S</Emphasis>)-7,7-dimethyl-2-oxo-3-oxabicyclo [4.1.0] hept-4-en-4-yl]methylene}-2-phenyl-l,3-oxazol-5(4H)-one

The (4Z)- {[(1R, 6S)-7,7-dimethyl-2-oxo-3-oxabicyclo[4.1.0]hept-4-en-4-yl]methylene}-2-phenyl-1,3-oxazol-5(4H)-one compound is synthesized and its molecular structure is determined.     

Synthesis of (<Emphasis Type="Italic">S</Emphasis>)-(-)-1,4-diaryl-6-methyl-4-trifluoromethyl-3,4-dihydropyrimidine-2(1<Emphasis Type="Italic">H</Emphasis>)-thiones

(S)-(+)-4-Amino-4-aryl-5,5,5-trifluoropentan-2-one reacted with aryl isothiocyanates containing electron-withdrawing substituents to give (S)-(−)-1,4-diaryl-6-methyl-4-trifluoromethyl-3,4-dihydropyrimidine-2(1H)-thiones.     

Regioselectivity of the interaction of (1<Emphasis Type="Italic">S</Emphasis>,2<Emphasis Type="Italic">S</Emphasis>)-2-amino-1-(4-nitrophenyl)-1,3-propanediol with some symmetrical ketones

The interaction of (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediol with a series of symmetrical ketones has been studied. As a result isomeric oxazolidines are formed in a ratio of 85:15. These oxazolidines were shown to decompose readily under the action of hydrazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1518–1523, October, 2004.     

Synthesis and crystal structure of (2<Emphasis Type="Italic">S</Emphasis>,4<Emphasis Type="Italic">S</Emphasis>,5<Emphasis Type="Italic">R</Emphasis>)-2-(5-bromo-2-hydroxyphenyl)-3,4-dimethyl-5-phenyl-1,3-oxazolidines

Condensation of ephedrine alkaloids with 5-bromo-2-hydroxybenzaldehyde was studied, and X-ray diffraction analysis of the synthesized (2S,4S,5R)-2-(2-hydroxy-5-bromophenyl)-3,4-dimethyl-5-phenyl-1,3-oxazolidines was performed.     

Synthesis,structures, and photochromic properties of 3-[(<Emphasis Type="Italic">E</Emphasis>)-alk-1-enyl]-4-(1-alkyl-5-methoxy-2-methyl-1<Emphasis Type="Italic">H</Emphasis>-indol-3-yl)furan-2,5-diones

New hetarylethenes, viz., 3-[(E)-alk-1-enyl]-4-(1-alkyl-5-methoxy-2-methyl-1H-indol-3-yl)furan-2,5-diones, exhibiting photochromic properties in solution were synthesized. The molecular and crystal structure of 3-(5-methoxy-1,2-dimethyl-1H-indol-3-yl)-4-[(E)-prop-1-enyl]furan-2,5-dione was determined by X-ray diffraction. The initial and photoinduced forms of hetarylethenes are characterized by thermal stability. The open-ring isomers of furandiones exhibit fluorescence with quantum yields of up to 0.1.     

Phenolic constituents from the stems of <Emphasis Type="Italic">Acanthopanax senticosus</Emphasis>

A new phenolic glycoside was isolated from the stems of Acanthopanax senticosus together with sixteen known compounds. The structure of the new compound was determined to be 2,6-dimethoxy-4-[(1E)-3,3-dimethoxy-1-propenyl]phenyl β-D-glucopyranoside (1) by means of physical, chemical, and spectroscopic methods. Of the known compounds, salvadoraside (7), (7R,8S)-dihydrodehydrodiconiferyl alcohol 4,9′-di-O-β-D-glucopyranoside (8), 3-(4-O-β-D-glucopyranosylferuloyl)quinic acid (15), rel-5-(1R,5S-dimethyl-3R,4R,8S-trihydroxy-7-oxa-6-oxobicyclo[3,2,1]oct-8-yl)-3-methyl-2Z,4E-pentadienoic acid (16), and lycoperodine-l (17) were first reported from the title plant. The inhibitory activities of the isolated compounds against α-glucosidase from rat intestine were also reported.     

Regioselective synthesis of polyfluoroalkyl-substituted 7-(1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-1-yl)-6,7-dihydro-1<Emphasis Type="Italic">H</Emphasis>-indazol-4(5<Emphasis Type="Italic">H</Emphasis>)-ones

3-Polyfluoroalkyl-6,6-dimethyl-7-(1H-1,2,3-triazol-1-yl)-6,7-dihydro-1H-indazol-4(5H)-ones were synthesized with high regioselectivity by 1,3-dipolar cycloaddition of terminal alkynes (phenylacetylene, hex- 1-yne, hept-1-yne, and but-3-yn-1-ol) to 7-azido-6,6-dimethyl-3-polyfluoroalkyl-6,7-dihydro-1H-indazol-4(5H)-ones which were prepared by bromination of 6,6-dimethyl-3-polyfluoroalkyl-6,7-dihydro-1H-indazol- 4(5H)-ones with N-bromosuccinimide in anhydrous carbon tetrachloride, followed by treatment of the corresponding 7-bromo derivatives with sodium azide.