نتایج جستجو برای: 8 dioxo octahydro xanthenes
تعداد نتایج: 656603 فیلتر نتایج به سال:
Four lanostane triterpenes, 3,7,11-trioxo-5α-lanosta-8,24(E)-dien-26-oic acid, methyl 11α-3,7-dioxo-5α-lanosta-8,24(E)-dien-26-oate, methyl 3,7,11,12,15,23-hexaoxo-5α-lanost-8-en-26-oate, and ethyl 3,7,11,12,15,23-hexaoxo-5α-lanost-8-en-26-oate, two sterols, (14α,22E)-14-hydroxyergosta-7,22-diene-3,6-dione and a steroid named as camphosterol A were isolated from a mixture of fruiting bodies and...
From ethyl acetate-methanol extracts of leaves and twigs of Pseuduvaria trimera a new aporphine alkaloid; 8-hydroxy-1,4,5-trimethoxy-7-oxoaporphine or 8-hydroxyartabonatine C (1) was isolated, together with the known 1,2,3-trimethoxy-4,5-dioxo-6a,7-dehydroaporphine (ouregidione, 2). Their structures were elucidated by a combination of spectral methods; mainly 2D NMR; IR and MS. Compounds 1 and ...
According to the principles of the methodology of bioisosteric replacements a series of methyl 1-R-4-methyl-2,2-dioxo-1H-2λ⁶,1-benzothiazine-3-carboxylates has been obtained as potential analgesics. In addition, a fundamentally new strategy for the synthesis of compounds of this chemical class involving the introduction of N-alkyl substituent at the final stage in 2,1-benzothiazine nucleus alre...
The high valent molybdenum-dioxo complex [MoO2Cl2] catalyzes the addition of dimethylphenylsilane to aldehydes and ketones to afford the corresponding dimethylphenylsilyl ethers in quantitative yield.
In the title mol-ecular salt [systematic name: triethyl-ammonium 1,3-dimethyl-2,6-dioxo-5-(2,4,6-trinitro-phen-yl)-1,2,3,6-tetra-hydro-pyrimidin-4-olate], C(6)H(16)N(+)·C(12)H(8)N(5)O(9) (-), the dihedral angle between the aromatic rings in the anion is 46.88 (8)°. The nitro group para to the ring junction is almost coplanar with its attached ring [dihedral angle = 0.76 (3)°], but the two ortho...
During the development of a new regiospecific synthetic methodology for 1,5 dihydroxy- 9,lO-anthraquinone, it was observed that (anthrufin) preparative TLC of 1,2,3,4,5,6,7,8-octahydro-9,lO-dihyd roxy- 1,5-anthracenedione on silica gel produced a well-defined 1:l complex of the dione and an aerial oxidation product of it, the quinone dimethide 1,2,3,4,5,6,7- hexahydro-9,lO-dihydroxy-1 ,5-...
Abstract Pure-organic red exciplex emitters are far from satisfactory in terms of quantity and efficiency. The narrow lowest unoccupied molecular orbital (LUMO) energy levels range reported acceptors together with the intrinsic exciton non-radiative decay dominant factors restricting progress exciplexes. Herein, two acceptor molecules operating at unique LUMO -3.51 -3.56 eV, namely 4-(6-([1, 1’...
The title compound, C(33)H(34)N(4)O(2)S·CH(3)OH, was prepared as a spiro-lactam ring formation of rhodamine 6 G dye for comparison with a ring-opened form. The xanthene and spiro-lactam rings are approximately planar [r.m.s. deviations from planarity = 0.122 (3) and 0.072 (6) Å, respectively]. The dihedral angles formed by the spiro-lactam and thio-phene rings with the xanthene ring system are ...
In the title compound, C25H29FO4, each cyclo-hexenone ring has an envelope conformation with the dimethyl-substituted atom as the flap. The hy-droxy and carbonyl groups form two intra-molecular O-H⋯O hydrogen bonds, as is typical for xanthene derivatives. In the crystal, very weak C-H⋯O hydrogen bonds link mol-ecules into dimers.
The stabilized conformation of the title compound, C(36)H(25)NO(3), 4-(9-anthryl)-1-(2-methoxyphenyl)-spiro[azetid-in-3,9'-xanthen]-2-one, may be compared with that of the isomeric compound 4-(9-anthr-yl)-1-(4-methoxy-phen-yl)spiro-[azetidin-3,9'-xanthen]-2-one. In the title isomer, the meth-oxy group is slightly twisted out of the plane of the attached benzene ring, with a C-O-C-C torsion angl...
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