Crystal structures of 1,1,1-trifluoro-4-hydroxy-4-phenyl-but-3-en-2-one, 2,2,6,6-tetramethyl-3-hydroxy-hept-3-en-5-one, 2,2,6,6-tetramethyl-3-methylamino-hept-3-en-5-one and a study of the ability of these ligands to complex formation with metals

Crystal structures are determined (Bruker Nonius X8 Apex, 4K CCD-detector, λMoK _α, graphite monochromator, T 150 K and 293 K) for two β-diketones F₃CC(O)CH₂C(O)Ph (1) (space group P2₁/c, a = 7.0713(3)Å, b = 11.5190(6)Å, c = 11.3602(6) Å, β = 99.405(2)°, V = 912.90(8) ų, Z = 4), (CH₃)₃CC(O)CH₂C(O)C(CH₃)₃ (2) (space group Pbca, a = 11.5536(8) Å, b = 11.5796(10) Å, c = 17.2523(13) Å, V = 2308.1(3) ų, Z = 8) and a ketoimine (CH₃)₃CC(NCH₃)CH₂C(O)C(CH₃)₃ (3) (space group I4₁/a, a = 18.7687(6) Å, b = 18.7687(6) Å, c = 14.5182(6) Å, V = 5114.2(3) ų, Z = 16). All structures are molecular and comprise isolated molecules joined by van der Walls interactions. The substitution energy of a Na atom for a hydrogen atom in free ligands is calculated by the hybrid B3LYP quantum chemical method. A successful preparation of Na(I) chelates with ligands 1, 2 and failed attempts to prepare a complex with ligand 3 are in accordance with the calculations. Geometrical simulation of a copper(II) complex with ligand 3 reveals the overlap of CH₃ groups which hinders the complexation.     

Solid-state photodimerization of cholest-4-en-3-one

Crystalline cholest-4-en-3-one undergoes solid-state dimerization by UV radiation to give two ring A - ring A connected dimers. No dimerization occurs in solution. The first dimer, characterized by a cyclobutane ring, is formed by connection of C-2 and C-3 of a moiety with C-5' and C-6' of another moiety, respectively. The latter dimer has a six-membered ketal ring formed by connection of C-2 with C-5' and of O, linked to C-3, with C-3'. The structures have been determined by spectroscopic means. X-ray analysis of title compound evidences the proximity of the axial H-2 of a molecule to the C-4' of a molecule in the upper layer. The transfer of the hydrogen and the connection between C-2 and C-5' might be the driving force of dimerization.     

Synthesis and structure of trifluoromethylated arylhydrazones formed from coupling of 4-(dimethylamino)-1,1,1-trifluorobut-3-en-2-one with diazonium salts

A series of trifluoromethyl-containing arylhydrazones were prepared via a direct azo-coupling of (E)-4-(dimethylamino)-1,1,1-trifluorobut-3-en-2-one (1) with different aromatic diazonium salts. Furthermore, we also discussed the non-covalent interactions existing in the crystal structure of compound (E)-4,4,4-trifluoro-2-(2-(4-iodophenyl)hydrazono)-3-oxobutanal (3c) by the X-ray diffraction analysis.     

18-甲基腺甾烯酮一类物的酶催化羟化

18-甲基-11α-羟基腺甾-4-烯-3,17-双酮是合成高效口服避孕药的重要中间体。试用黑根霉酶羟化引进11α-羟基于18-甲基-19-失碳雌甾-4-烯-3,17-双酮,得到包括该化合物在内的几种不同位置羟基产物的混合物。改用赭曲霉酶羟化同一底物也得到包括11α-羟基在内的几种不同位置羟基产物的混合物。而用赭曲霉催化羟化18-甲基-17β-羟基腺甾-4-烯-3-酮时,首次得到15α-羟化的主要产物和7β羟化的次要产物。前者可用来合成另一类高效口服避孕药△^15-D-18-甲基炔诺酮。     

Hydroarylation of 2-azabicyclohept-5-en-3-one

The hydroarylation of 2-azabicyclo[2.2.1]hept-5-en-3-one with a range of aryl iodides is presented.     

Domain structure of organic crystals. Crystal structure of 3-bromobicyclo[3. 3. 1]non-2-en-4-one

M. V. Lomonosov Moscow State University. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 6, pp. 104–107, November–December, 1990.     

The stereochemistry of the product derived from the base-catalyzed dimerization of 3-methylcyclohex-2-en-1-one

Single-crystal X-ray analysis of the product derived from the base-catalyzed dimerization of 3-methylcyclohex-2-en-1-one has established that it possesses a saturated diketone structure with a syn-stereochemistry rather than an anti-arrangement as previously proposed.     

18-甲基腺甾烯酮一类物的酶催化羟化

18-甲基-11α-羟基腺甾-4-烯-3,17-双酮是合成高效口服避孕药的重要中间体。试用黑根霉酶羟化引进11α-羟基于18-甲基-19-失碳雌甾-4-烯-3,17-双酮,得到包括该化合物在内的几种不同位置羟基产物的混合物。改用赭曲霉酶羟化同一底物也得到包括11α-羟基在内的几种不同位置羟基产物的混合物。而用赭曲霉催化羟化18-甲基-17β-羟基腺甾-4-烯-3-酮时,首次得到15α-羟化的主要产物和7β羟化的次要产物。前者可用来合成另一类高效口服避孕药△^15-D-18-甲基炔诺酮。     

The photochemistry of 4-(n-methylanilino)-pent-3-en-2-one

Low conversion irradiation studies indicate that the cis and trans 3-acetyl-1,2-dimethylindolines are intermediate products in the photosynthetic production of 1,2-dimethylindole from 4-(N-methylanilino)-pent-3-en-2-one.     

Synthesis of azolo[a]pyridines from 5-(bromomethyl)hept-4-en-3-one and 5-bromopent-3-en-2-one derivatives

Alkyl derivatives of 1H-imidazo[1,2-a]pyridin-4-ium, 5H-pyrido[1,2-a]benzimidazol-10-ium, 1H-[1,2,4]-triazolo[4,3-a]pyridin-4-ium, and 3-methylthiazolo[3,2-a]pyridin-4-ium bromides were obtained in two stages from (4Z)-5-(bromomethyl)-2,2,6,6-tetramethylhept-4-en-3-one, 5-bromo-4-methylpent-3-en-2-one, or (3E)-5-bromopent-3-en-2-one by alkylation of 1-alkyl-1H-imidazoles, 1-alkyl-1H-benz-imidazoles, 1-methyl-1H-1,2,4-triazole, and 4-methylthiazole and subsequent cyclization of the quaternary azolium salts in the presence of bases.     

Reactions of tri- and hexafluoroacetylacetones and 4-ethoxy-1,1,1-trifluorobut-3-en-2-one with 2-aminobenzohydrazide

Reactions of 1,1,1-trifluoropentane-2,4-dione and 1,1,1,5,5,5-hexafluoropentane-2,4-dione with 2-aminobenzohydrazide afforded (2-aminophenyl)[5-hydroxy-3-methyl-5-(trifluoromethyl)- and (2-aminophenyl)[ 5-hydroxy-3,5-bis(trifluoromethyl)-4,5-dihydropyrazol-1-yl]methanones, respectively. 4-Ethoxy-1,1,1- trifluorobut-3-en-2-one reacted with 2-aminobenzhydrazide to give 2-(trifluoromethyl)-3a,4-dihydropyrazolo-[5,1-{ptb}]quinazolin-9(3{ptH})-one.     

Diastereoselective formation of 2-aryl-3-arenesulfonyl 4-ethyl-1,3-oxazolidines: An X-ray crystallographic and H NMR study

N-Arylsulfonamides of (R)- and (S)-2-amino-1-butanol, on condensation with aromatic aldehydes produced diastereomerically pure 2-aryl-3-arenesulfonyl 4-ethyl-1,3-oxazolidines. The absolute configurations of one enantiomeric pair have been determined from two fully refined X-ray structures, supplemented by nmr data.     

Synthesis and structure of 2,4-di-tert-butyl-1-chloro-6-methyltricyclo[4.1.0.02,7]hept-4-en-3-one

The reaction of 2,6-di-tert-butyl-4-dichloromethyl-4-methylcyclohexa-2,5-dien-1-one with (Me₃Si)₂NNa yielded 2,4-di-tert-butyl-1-chloro-6-methyltricyclo[4.1.0.0^2,7]hept-4-en-3-one (substituted tropovalene). The structure of the title compound was established by¹H and¹³C NMR spectroscopy and X-ray diffraction analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1642–1645, September, 1997.