Synthesis and Photochemical Trasformations of 19-Phenylsulfonyl Provitamin D Analogue

1998 ◽  
Vol 63 (10) ◽  
pp. 1597-1612
Author(s):  
Piotr Grzegorzewski ◽  
Izabela Koladkiewicz ◽  
Jacek W. Morzycki ◽  
Rafal R. Sicinski
Keyword(s):  
Double Bond ◽  
Uv Irradiation ◽  
Efficient Method ◽  
Nmr Spectra ◽  
Complex Mixture ◽  
The Other ◽  
Allylic Oxidation ◽  
H Nmr ◽  
Nucleophilic Displacement ◽  
Displacement Reactions

The synthesis of provitamin D analogue 19-(phenylsulfonyl)androsta-5,7-diene-3β,17β-diyl 3-acetate 17-pivalate (20) has been accomplished from 19-hydroxyandrost-5-ene-3β,17β-diyl 3-acetate 17-pivalate. 19-(Phenylsulfonyl)androst-5-ene-3β,17β-diyl 3-acetate 17-pivalate (10), a precursor of 20, was first obtained in low yield in the nucleophilic displacement reactions of 19-halogenated-5-ene steroids with sodium benzenesulfinate. Then a more efficient method has been used, which involves protection of the double bond as an epoxide. Introduction of the C(7)-C(8) double bond into olefin 10 has been also achieved in two ways. The first involved bromination-dehydrobromination and the other consisted of an allylic oxidation of olefin 10 leading to enone and the Bamford-Stevens reaction of its tosylhydrazone. UV irradiation of 5,7-diene 20 resulted in formation of a complex mixture of products. The structures of five isolated compounds were established on the basis of their 1H NMR spectra and mechanistic rationale.

Synthesis and reactions of alkyl 3-bromomethyl-3-(2-furyl)-2-propenoates with sulfur containing nucleophiles

1980 ◽  
Vol 45 (1) ◽  
pp. 142-149 ◽  
Author(s):  
Katarína Špirková ◽  
Jaroslav Kováč ◽  
Václav Konečný ◽  
Miloslava Dandárová ◽  
Marta Černayová
Keyword(s):  
Nmr Spectra ◽  
H Nmr ◽  
Nucleophilic Displacement ◽  
Displacement Reactions ◽  
Sulfur Containing

Preparation and nucleophilic displacement reactions of alkyl 3-bromomethyl-3-(2-furyl)-2-propenoates with sulfur containing nucleophiles is described. The UV, IR and 1H-NMR spectra of the synthesized compounds are interpreted.

15N, 13C, and 1H NMR Spectra of Azo and Hydrazo Compounds Derived from 1,3,3-Trimethyl-2-methylidene-2,3-dihydroindole (Fischer Base)

1998 ◽  
Vol 63 (7) ◽  
pp. 1012-1020 ◽  
Author(s):  
Antonín Lyčka ◽  
Josef Jirman ◽  
Alois Koloničný
Keyword(s):  
Double Bond ◽  
Hydrochloric Acid ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
Azo Compounds ◽  
Passive Component ◽  
Geometric Isomers ◽  
H Nmr ◽  
Fischer Base ◽  
Hydrazone Form

The 15N, 13C, and 1H NMR spectra were measured for azo and hydrazo compounds derived from 1,3,3-trimethyl-2-methylidene-2,3-dihydroindole (Fischer base), which is a passive component with a terminal methylidene group. Products prepared by coupling in hydrochloric acid exist in the corresponding hydrazone form as the E-isomers. Neutralization gives a mixture of two isomeric azo compounds which differ in the arrangement at the C(2)=C(10) double bond. This mixture was alkylated with methyl iodide to obtain the =N-N(CH3)- hydrazone derivatives. The geometric isomers were resolved based on the NOESY approach and the stereospecific behaviour of the 2J(15N,13C) coupling constants was studied for the 15N-labelled compounds.

Preparation of New Oxidized 18-α-Oleanane Derivatives

2005 ◽  
Vol 70 (9) ◽  
pp. 1447-1464 ◽  
Author(s):  
Miroslav Kvasnica ◽  
Iva Tišlerová ◽  
Jan Šarek ◽  
Jan Sejbal ◽  
Ivana Císařová
Keyword(s):  
Double Bond ◽  
Nmr Spectra ◽  
Biological Activities ◽  
Oxidative Cleavage ◽  
Allylic Oxidation ◽  
Unsaturated Ketone ◽  
Ruthenium Tetroxide ◽  
Unsaturated Compounds ◽  
Starting Compound ◽  
C Nmr

19β,28-Epoxy-4,5-seco-3,5-cyclo-18α-olean-3(5)-ene (2) is an appropriate compound for oxidations, which lead to new oxidized compounds with potential biological activities. Several oxidations were used such as epoxidation, allylic oxidation, oxidative cleavage of double bond and other ones. From the starting compound epoxides 3a, 3b and unsaturated ketone 4 were prepared. This ketone was further oxidized to diketone 6 and anhydride 7. The double bonds of all unsaturated compounds were cleaved with ruthenium tetroxide to afford new A-seco oleananes. The structure and stereochemistry of the compounds were derived from IR, MS, 1H and 13C NMR spectra (1D and 2D COSY, TOCSY, NOESY, HSQC, HMBC).

scholarly journals Crystal structure and solvent-dependent behaviours of 3-amino-1,6-diethyl-2,5,7-trimethyl-4,4-diphenyl-3a,4a-diaza-4-bora-s-indacene

2017 ◽  
Vol 73 (3) ◽  
pp. 378-382
Author(s):  
Lijing Yang ◽  
Brett Drew ◽  
Ravi Shekar Yalagala ◽  
Rameez Chaviwala ◽  
Razvan Simionescu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Fluorescence Spectroscopy ◽  
Title Compound ◽  
Nmr Spectra ◽  
Membered Ring ◽  
The Other ◽  
Time Dependent ◽  
H Nmr ◽  
The Mean ◽  
Over Time

In the title compound (3-amino-4,4-diphenyl-BODIPY), C28H32BN3, the central six-membered ring has a flattened sofa conformation, with one of the N atoms deviating by 0.142 (4) Å from the mean plane of the other five atoms, which have an r.m.s. deviation of 0.015 Å. The dihedral angle between the two essentially planar outer five-membered rings is 8.0 (2)°. In the crystal, molecules are linkedviaweak N—H...π interactions, forming chains along [010]. The compound displays solvent-dependent behaviours in both NMR and fluorescence spectroscopy. In the1H NMR spectra, the aliphatic resonance signals virtually coalesce in solvents such as chloroform, dichloromethane and dibromoethane; however, they are fully resolved in solvents such as dimethyl sulfoxide (DMSO), methanol and toluene. The excitation and fluorescence intensities in chloroform decreased significantly over time, while in DMSO the decrease is not so profound. In toluene, the excitation and fluorescent intensities are not time-dependent. This behaviour is presumably attributed to the assembly of 3-amino-4,4-diphenyl-BODIPY in solution that leads to the formation of noncovalent structures, while in polar or aromatic solvents, the formation of these assemblies is disrupted, leading to resolution of signals in the NMR spectra.

5J(CH3,SH) as a negative proximate or as a positive σ−π coupling in 2-methylthiophenol derivatives

1985 ◽  
Vol 63 (8) ◽  
pp. 2217-2220 ◽  
Author(s):  
Ted Schaefer ◽  
James Peeling ◽  
Rudy Sebastian ◽  
James D. Baleja
Keyword(s):  
Nmr Spectra ◽  
Sulfhydryl Group ◽  
The Other ◽  
Coupling Mechanism ◽  
Methyl Group ◽  
Tert Butyl ◽  
H Nmr ◽  
Out Of Plane ◽  
Negative Coupling

Analyses of the 1H nmr spectra of 6-chloro-2-methylthiophenol and of 4-tert-butyl-2-methylthiophenol in CCl4 solution, together with double irradiation experiments, show that 5J(CH5,SH) in the former compound is −0.66 Hz and is +0.47 Hz in the latter. In the chloro compound, the sulfhydryl group spends relatively little time in out-of-plane conformations at 300 K. The negative coupling is a consequence of a through-space or proximate coupling mechanism. In the other compound, the sulfhydryl group samples many out-of-plane conformations but relatively few in which the S—H bond lies near the methyl group. Therefore 5J(CH3,SH) is now dominated by a σ−π electron mechanism and is positive. Probably by coincidence, 4J(H,SH) in this compound is equal in magnitude but opposite in sign to 5J(CH3,SH).

scholarly journals Komplexchemie polyfunktioneller Liganden, 52 [1]. Hydrido- und Deuterido-mangan(I)-carbonyl-Komplexe des 1.1.1- Tris (diphenylphosphinomeihy 1) ethans / Complex Chemistry of Polyfiinctional Ligands, 52 [1]. Hydrido- and Deuterido-manganese(I)-carbonyl Complexes of 1,1,1 -Tris(diphenylphosphinomethyl)ethane

1979 ◽  
Vol 34 (6) ◽  
pp. 799-804 ◽  
Author(s):  
Jochen Eilermann ◽  
Helmut A. Lindner
Keyword(s):  
Uv Irradiation ◽  
Methyl Alcohol ◽  
Ultraviolet Irradiation ◽  
Nmr Spectra ◽  
Carbonyl Complexes ◽  
Decomposition Products ◽  
H Nmr ◽  
Acetone Water ◽  
Complex Chemistry ◽  
New Compounds

[Mn(CO)3(R2PCH2)3CCH3]ClO4 (1a) (R = C6H5) reacts with NaBH4 on UV irradiation to yield HMn(CO)2(R2PCH2)3CCH3 (2a). [Mn(CO)3(R2PCH2)3CCH3]BR4 (1b) gives only decomposition products. Boiling of 1a or b and NaOH in acetone/water does nots give 2a but the new hydride HMn(CO)3(R2PCH2)2C(CH3)CH2PR2 (3a). This compound cannot be prepared on ultraviolet irradiation of a solution of 1a or b and NaBH4 in methyl alcohol or acetone. The analogous deutendes DMn(CO)2(R2)PCH2)3CCH3 (2b) and DMn(CO)3(R2PCH2)2C(CH3)CH2PR2 (3b) were also prepared. The new compounds were characterized by their IR, Raman, 1H NMR and 31P NMR spectra.

Analysis of 1H-NMR spectra of cinnamaldehyde type model substances of lignin

1980 ◽  
Vol 45 (2) ◽  
pp. 330-334 ◽  
Author(s):  
Tibor Liptaj ◽  
Milan Remko ◽  
Ján Polčin
Keyword(s):  
Double Bond ◽  
Nmr Spectra ◽  
Side Chain ◽  
Type Model ◽  
Stable Conformer ◽  
Spectra Analysis ◽  
H Nmr ◽  
Nmr Data ◽  
Lignin Model ◽  
Model Substances

1H-NMR spectra of the following lignin model substances have been analyzed: cinnamaldehyde, 2-methoxycinnamaldehyde, 3-methoxycinnamaldehyde, 4-methoxycinnamaldehyde, 3,4-dimethoxycinnamaldehyde, 3-methoxy-4-hydroxycinnamaldehyde and 3,4,5-trimethoxycinnamaldehyde. From the NMR spectra analysis it follows that the studied compounds exist in solutions as trans isomers. Theoretical (PCILO) calculations in agreement with the NMR data have shown that the more stable conformer has trans orientation of C=O group with respect to the double bond of the conjugated side chain.

Cyclopentadienyl–metal bond cleavage and stereospecific bromination. The structure of (η-C5H5)2Ti(OOCPh)2 and its reactions with bromine

1988 ◽  
Vol 66 (3) ◽  
pp. 429-434 ◽  
Author(s):  
C. Robert Lucas ◽  
Eric J. Gabe ◽  
Florence L. Lee
Keyword(s):  
Nmr Spectra ◽  
Bond Cleavage ◽  
The Other ◽  
Ring Cleavage ◽  
Radical Mechanism ◽  
Iodine Monochloride ◽  
Carboxylate Ligands ◽  
X Ray ◽  
H Nmr ◽  
Using Data

The 13C and 1H nmr spectra as well as the X-ray structure determination for (η-C5H5)2Ti(OOCPh)2 are described. The compound crystallizes in space group P21212I with a = 7.5135, b = 12.5166, c = 21.1416 Å, Z = 4, dcalcd = 1.40 g cm−3 (MoKα1, λ = 0.70932 Å). The structure was solved with MULTAN using data collected at 115 K and refined to the final R = 0.059 for 1500 significant reflections. The molecule has two different carboxylate ligands, one of which has a Ti—O—C angle of 135.4(6)° and longer Ti—O (1.976(5) Å) and O—C (1.300(10) Å) bonds while the other has a Ti—O—C angle of 157.0(7)° with shorter Ti—O (1.913(6) Å) and O—C (1.267(10) Å) bonds. With bromine, ring cleavage occurs giving C5H5Br3 or C5H5Br5 in which bromination has occurred stereospecifically. The same reaction occurs with chlorine but not with iodine or iodine monochloride. Related reactions have been observed with (η-C5H5)2MCl2 (M = Ti, Zr, and V). A non-radical mechanism is proposed in which the LUMO and HOMO of Br2 interact simultaneously with one cyclopentadienyl ring and with the metal. This interaction is a consequence of the structure of (η-C5H5)2M(OOCPh)2.

Preparation of C(18)-empiric 20,29,30-trinorlupane derivatives. 1H, 13C NMR and mass spectra

1986 ◽  
Vol 51 (3) ◽  
pp. 621-635 ◽  
Author(s):  
Václav Křeček ◽  
Jiří Protiva ◽  
Miloš Buděšínský ◽  
Eva Klinotová ◽  
Alois Vystrčil
Keyword(s):  
Nitrous Acid ◽  
Mass Spectra ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Allylic Oxidation ◽  
Hydroxyl Group ◽  
Methyl Groups ◽  
Unsaturated Ketone ◽  
H Nmr ◽  
C Nmr

Reaction of amide I with nitrous acid gave the olefins II, III and IV. On allylic oxidation of olefin IV α,β-unsaturated ketone V is formed from which olefins VIII and IX were prepared by a sequence of further reactions. Addition of hydrogen to the double bond of olefin IV and α,β-unsaturated ketone V takes place on catalytic hydrogenation from the β-side and leads to derivatives with cis-annellated rings D/E. This made the preparation of hydrocarbons VI and VII epimeric on C(18) possible, which represent reference compounds for the study of the effect of substituents on the chemical shifts of the methyl groups and the saturated carbon atoms of 18αH and 18βH-lupane derivatives. The configuration of the hydroxyl group in epimers XI and XII were derived from 1H NMR spectra. Deuteration of olefins III, IV and IX gave deuteriohydrocarbons XVI to XVIII. The 1H, 13C NMR and mass spectra of the substances prepared are discussed.

1H NMR spectra of some chloro-alkenes

1981 ◽  
Vol 46 (11) ◽  
pp. 2924-2934
Author(s):  
Seán Cawley ◽  
Jan Schraml ◽  
Petr Svoboda ◽  
Robert Ponec ◽  
Václav Chvalovský
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Dipole Moments ◽  
Coupling Constants ◽  
The Other ◽  
Dominant Factor ◽  
Proton Proton ◽  
Electric Field Effects ◽  
H Nmr ◽  
Proton Coupling

1H NMR spectra and electric dipole moments of a series of propene derivatives, (CH3)3-nCln.CCH=CH2 (n = 0-3), were measured and the spectra analyzed. Discrepancies in literature data on compounds with n = 0 and 3 are probably due to systematic spectrometer errors. Vinylic proton chemical shifts are found to vary linearly with n in the direction expected on the electronegativity ground (the variations with n occurs in the order HA > HB ≥ HC). Calculations show that even with the extreme reported values of C-C and C-Cl bond magnetic anisotropies, the shift variations with n cannot be accounted for by magnetic anisotropy effects of a freely rotating (CH3)3-nClnC group. Similar calculations rule out electric field effects as the dominant factor. On the other hand, the electron charge distribution, as obtained from CNDO/2 calculations, including d-orbitals and employing Del Bene-Jaffé parametrization, is linearly related to the vinylic proton shifts. This finding supports the earlier interpretation of NMR spectra of vinylsilanes in terms of back-bonding. The vinyl proton-proton coupling constants decrease with increasing n, the changes being larger in the constants which couple proton A (cis) to the other two.

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