Epimeric 17-hydroxy derivatives of 14β-androst-5-en-3β-yl acetate

1990 ◽  
Vol 55 (10) ◽  
pp. 2510-2520 ◽  
Author(s):  
Ivan Černý ◽  
Vladimír Pouzar ◽  
Miloš Buděšínský ◽  
Pavel Drašar ◽  
Miroslav Havel
Keyword(s):  
Sodium Nitrite ◽  
Sodium Borohydride ◽  
Nmr Spectra ◽  
H Nmr ◽  
Derivatives Of ◽  
Androstane Derivatives

A new, six-step synthesis of 3β-hydroxy-14β-androst-5-en-17-one (IX) starting from 3β-hydroxyandrost-5-en-17-one has been elaborated. Reduction of acetate X with sodium borohydride afforded 17α-hydroxy-14β-androst-5-en-3β-yl acetate (XI). The corresponding 17β-derivative XIV was obtained by epimerization of 17α-O-tosyl derivative XIII with sodium nitrite in hexamethylphosphoramide. The 13C and 1H NMR spectra of 14β-androstane derivatives are discussed.

Preparation of 12,20-disubstituted lupane derivatives

1979 ◽  
Vol 44 (1) ◽  
pp. 194-210 ◽  
Author(s):  
Vladimír Pouzar ◽  
Alois Vystrčil
Keyword(s):  
Hydroxy Group ◽  
Sodium Borohydride ◽  
Nmr Spectra ◽  
Unsaturated Ketone ◽  
Lithium Aluminium Hydride ◽  
H Nmr ◽  
Unsaturated Alcohols ◽  
Lithium Aluminium ◽  
Primary Hydroxy Group ◽  
Derivatives Of

Ketoester I was reduced to diol VI. The higher reactivity of its primary hydroxy group was made use of for the preparation of 12α-hydroxy derivatives VII, VIII and X the oxidation of which led to oxo derivatives XII, XIII and XIV. The reduction of the 12-oxo group in compounds XII and XIV with lithium aluminium hydride takes place stereospecifically under formation of 12α-hydroxy derivatives VII and X, while on reduction with sodium in 1-propanol corresponding 12β-hydroxy derivatives XV and XVI are also formed. Reduction of the unsaturated ketone XVII with sodium borohydride gave unsaturated alcohols XVIII and XX. As acetoxy ketone XXIV was obtained from olefin XIX in a 12% yield only, its alternative preparation was carried out from acetoxy ketone XXXIV via the intermediates XXXII, XXXV, XXVIII and XXXI in an overall yield of 27%. The structures of the derivatives of 12-lupene (III, V, XVII, XIX and XXI), 12-lupanol (II, VII, X, XV, XXXI and XXVII) and 12-lupanone (I, XII, XIII, XIV, XXIII, XXIV, XXXIII and XXXIV) were confirmed by the analysis of their 1H NMR spectra.

Photoreaktionen von Dekacarbonyldirhenium mit Allen und unverzweigten Allenderivaten / Photoreactions of Decacarbonyldirhenium with Allene and Unbranched Derivatives of Allene

1995 ◽  
Vol 50 (4) ◽  
pp. 649-660 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Wolfgang Michels ◽  
Gerhard Heeb
Keyword(s):  
Nmr Spectra ◽  
Crystal And Molecular Structure ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Oxidative Rearrangement ◽  
Dirhenium Complexes ◽  
Derivatives Of ◽  
By Products

Decacarbonyldirhenium (1) reacts upon UV irradiation with allene (2), 1,2-butadiene (3) and 2,3-pentadiene (4) preferentially by CO substitution and oxidative rearrangement to the corresponding enneacarbonyl-μ-η1:3-endiyl-dirhenium complexes 5, 9, and 15 and to the octacarbonyl-μ-η2:2-allene-dirhenium complexes 6, the stereoisomers 10, 11, and 16. At elevated temperature 5, 9, and 15 loose CO and yield by a reductive rearrangement also the complexes 6, 10, 11, and 16. In addition to these main products, depending upon the allene derivative used, various by-products are obtained.By-products of the reaction o f 1 with 2 are octacarbonyl-μ-η3:3-(2,3-dimethylene-buta-1,4- diyl)dirhenium (7) and μ-η2:2-allene-hexacarbonyl-μ-η1:3-1-propene-1,3-diyl-dirheniurn (8). The photo reaction of 1 with 3 yields, in addition to 9-11, tetracarbonyl-η3-(E-5-ethylidene- 4-methyl-2-cyclopenten-1-yl)rhenium (12) and tetracarbonyl-η3-(Z-5-ethyliden-4- methyl-2-cyclopenten-1-yl)rhenium (13) as a mixture of isomers. 1 and 4 form the by-products tetracarbonyl-η3-(EZ-3-penten-2-yl)rhenium (17), tetracarbonyl-η3-(EE-3-penten-2-yl)rhenium (18) and heptacarbonyl-μ-η1:2:1:2-(4,5-dimethyl-2,6-octadiene-3,6-diyl)dirhenium (19) with an unusually bridging and chelating ligand. The constitutions of the reaction products have been concluded from the IR and 1H NMR spectra. For 19 the crystal and molecular structure has been determined by X-ray diffraction analysis.

Synthesis of Optically Active N6-Alkyl Derivatives of (R)-3-(Adenin-9-yl)-2-hydroxypropanoic Acid and Related Compounds

2003 ◽  
Vol 68 (5) ◽  
pp. 931-950 ◽  
Author(s):  
Marcela Krečmerová ◽  
Miloš Buděšínský ◽  
Milena Masojídková ◽  
Antonín Holý
Keyword(s):  
Nmr Spectra ◽  
Enantiomeric Purity ◽  
Optically Active ◽  
Secondary Amines ◽  
H Nmr ◽  
Alkyl Derivatives ◽  
Optically Pure ◽  
Derivatives Of ◽  
Related Compounds

Reaction of ethyl (R)-oxiranecarboxylate (2a) with various nucleobases (adenine, 6-chloropurine, thymine, cytosine, N6-benzoyladenine, 4-methoxy-5-methylpyrimidin-2(1H)-one and 4-methoxypyrimidin-2(1H)-one) afforded ethyl 3-substituted-2-hydroxypropanoates 4-10. Enantioselectivity of this reaction is dependent on the type of the base: 6-chloropurine, N6-benzoyladenine, 4-methoxy-5-methylpyrimidin-2(1H)-one, thymine and cytosine gave optically pure R enantiomers. In other cases, partial or complete racemization occurred. Optically pure ethyl (R)-3-(6-chloropurin-9-yl)-2-hydroxypropanoate (5a) was hydrolyzed to give (R)-3-(6-chloropurin-9-yl)-2-hydroxypropanoic acid (11). Reactions of 11 with various primary or secondary amines led to N6-substituted (R)-3-(adenin-9-yl)-2-hydroxypropanoic acids 14-19. Enantiomeric purity was determined from 1H NMR spectra measured in the presence of (-)-(R)-1-(9-anthryl)-2,2,2-trifluoroethan-1-ol.

Purine Nucleoside Analogues. 11. An Alternative Synthesis of N- and O-Alkyl Derivatives of 9- and 7-[(2-Acetoxyethoxy)methyl]-N2-acetylguanine

1999 ◽  
Vol 64 (4) ◽  
pp. 685-695 ◽  
Author(s):  
Marina Madre ◽  
Natella Panchenko ◽  
Alexander Golbraikh ◽  
Regina Zhuk ◽  
Upendra K. Pandit ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Room Temperature ◽  
Purine Nucleoside ◽  
Nucleoside Analogues ◽  
Alternative Synthesis ◽  
Restricted Rotation ◽  
H Nmr ◽  
Alkyl Derivatives ◽  
Derivatives Of ◽  
Conformational Calculations

Alkylations of 9- and 7-[(2-acetoxyethoxy)methyl]-N2-acetylguanine with alkyl halogenides in the presence of base have been investigated affording a new route to the preparation of 1,N2-dimethyl- as well as O6-benzyl-9(7)-alkoxyalkylguanines. 1H NMR spectra revealed that the 1,N2-dimethyl derivatives exist as mixtures of two conformers at room temperature due to the restricted rotation about the C2-N2 bond. These findings agreed with conformational calculations.

Synthesis of cyclopentane analogs of (2′- and 3′-deoxy-erythro-pentofuranosyl and ribofuranosyl)-2-thiouracil nucleosides

1986 ◽  
Vol 64 (8) ◽  
pp. 1620-1629 ◽  
Author(s):  
Lucjan J.J. Hronowski ◽  
Walter A. Szarek
Keyword(s):  
Sulfur Atom ◽  
Nmr Spectra ◽  
Aqueous Ammonia ◽  
Synthetic Route ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Synthetic Intermediates ◽  
Derivatives Of ◽  
Sulfur Containing ◽  
Sulfur Containing Compounds

Three new carbocyclic analogs of nucleosides having the 2-thiouracil base have been synthesized. The cyclopentyl groups in these nucleosides are (±)-{(1β,3α,4β)-3-hydroxy-4-(hydroxyrnethyl)cyclopentyl} (see 31), (±)-{(1β,2α,4β)-2-hydroxy-4-(hydroxymethyl)cyclopentyl} (see 32), and (±)-{(1β,2α,3α,4β)-2,3-dihydroxy-4-(hydroxymethyl)cyclopentyl} (see 33). The nucleosides were prepared by coupling the appropriate hydroxy derivatives of cis-3-aminocyclopentanemethanol with 3-ethoxypropenoyl isothiocyanate (21) followed by cyclization in 15 N aqueous ammonia to give the 2-thiouracil nucleosides. In addition a modified and shortened synthetic route is described for the synthesis of (±)-(1β,2α,3α,4β)-4-amino-2,3-dihydroxy-cyclopentanemethanol (19). The 1H nmr spectra at 200 MHz of all of the synthetic intermediates, the 2-thiouracil nucleosides, and of the corresponding carbocyclic analogs of uracil nucleosides are discussed. It is shown that each nucleoside has a characteristically unique 1H nmr spectrum and that in general the protons in the sulfur-containing compounds resonate at lower fields than those in the corresponding oxygen-containing compounds. The magnitude of this downfield shift is inversely related to the number of bonds separating a particular proton from the sulfur atom.

Coordination compounds of indium. Part 44. The oxidation of indium(I) halides by tetrahalogeno-ortho-quinones

1988 ◽  
Vol 66 (11) ◽  
pp. 2935-2940 ◽  
Author(s):  
Theodore A. Annan ◽  
Dennis G. Tuck
Keyword(s):  
Coordination Compounds ◽  
Nmr Spectra ◽  
Dynamic Behaviour ◽  
Addition Product ◽  
Donor Ligands ◽  
Chelate Complexes ◽  
H Nmr ◽  
Anionic Complexes ◽  
Derivatives Of ◽  
C Nmr

The reaction of indium(I) halides (InX; X = Cl, Br, I) with tetrahalogeno-ortho-quinones (Y4C6O2; Y = Cl, Br) gives the oxidative addition product Y4C6O2InX, These compounds have been isolated as adducts with neutral bidentate donor ligands (N,N,N′,N′-tetramethylethanediamine (tmen), 1,10-phenanthroline) or as salts of the anionic complexes [Y4C6O2InCl2]− or [Y4C6O2In(Cl)Br]−. The number of coordinated tmen molecules, and hence the structure, depends on the method of preparation. Infrared, 1H NMR, and 13C NMR spectroscopy all confirm that these products are all substituted-catecholato derivatives of indium(III), and the structure of these various neutral or anionic derivatives is discussed. The temperature dependence of the 13C NMR spectra shows that the dynamic behaviour of these compounds (in d6-dmso) is similar to that observed in previous studies of indium(III) chelate complexes.

Derivatives of 5α-androstan-3α- and 3β-ol with acrylonitrile side chain

1991 ◽  
Vol 56 (12) ◽  
pp. 2906-2916 ◽  
Author(s):  
Vladimír Pouzar ◽  
Hana Chodounská ◽  
Ivan Černý ◽  
Pavel Drašar
Keyword(s):  
Double Bond ◽  
Nmr Spectra ◽  
Sodium Hydride ◽  
Coupling Constants ◽  
Side Chain ◽  
H Nmr ◽  
Derivatives Of

Aldehydes II - III were reacted with diethyl cyanomethylphosphonate and sodium hydride in 1,2-dimethoxyethane to give the respective pairs of unsaturated nitriles IVa and Va, VIa and VIIa, and VIIIa and IXa differing in configuration at the 20(21)-double bond. The pure isomers were obtained by chromatography on alumina, and the configuration at the double bond in them has been established on the basis of the coupling constants J(20, 21) in their 1H NMR spectra. Nitriles IVa - VIIa and IXa were converted via the corresponding hydroxy derivatives into hemisuccinates IVd - VIId and IXd, and into β-D-glucosides IVe - VIIe and IXe.

Hydrazine Derivatives of β-Dicarbonyl Compounds, Part I. Studies on Some Benzoylacetaldehyde Aroylhydrazones

1978 ◽  
Vol 33 (12) ◽  
pp. 1527-1534 ◽  
Author(s):  
Latif Rateb ◽  
B. Azmy ◽  
M. A. Nashed ◽  
M. F. Iskander
Keyword(s):  
Schiff Bases ◽  
Nmr Spectra ◽  
Open Chain ◽  
Dicarbonyl Compounds ◽  
Hydrazine Derivatives ◽  
H Nmr ◽  
Imine Form ◽  
Derivatives Of

Abstract A series of benzoylacetaldehyde benzoylhydrazones were prepared and characterised. Their UV, IR, and 1H NMR spectra suggest the enol-imine structure rather than the keto-imine form of analogous Schiff bases. The pKa values of these aroylhydrazones were also measured and correlated with the Hammet substitution constants. Attempted cyclizations of these open-chain aroylhydrazones afforded the corresponding 5-hydroxy-2-pyrazoline compounds rather than the expected pyrazoles.

Synthesis and properties of styryl derivatives of 2-furaldehyde

1981 ◽  
Vol 46 (2) ◽  
pp. 515-519 ◽  
Author(s):  
Viera Knoppová ◽  
Adolf Jurášek ◽  
Miloslava Dandárová ◽  
Jaroslav Kováč
Keyword(s):  
Nmr Spectra ◽  
Uv Spectra ◽  
H Nmr ◽  
Vilsmeier Formylation ◽  
Derivatives Of

Reaction of 4-X-benzyltriphenylphosphonium halides with 2-furaldehyde and subsequent Vilsmeier formylation gave 5-(4-X-styryl)-2-furaldehydes ( X = H, Cl, Br, CN, NO2, CH3, and COOCH3). The UV, IR and 1H-NMR spectra of the prepared substances are discussed and it is demonstrated that the compounds are (E) isomers. The UV spectra of 5-styryl-2-furaldehyde have been compared with those of its benzene analogue.

Synthesis and properties of silicon, germanium, and tin derivatives of cyclopentadienyltricarbonylrhenium

1981 ◽  
Vol 59 (10) ◽  
pp. 1455-1462 ◽  
Author(s):  
D. F. Dong ◽  
J. K. Hoyano ◽  
W. A. G. Graham
Keyword(s):  
General Formula ◽  
Raman Spectra ◽  
Ultraviolet Irradiation ◽  
Silicon Germanium ◽  
Nmr Spectra ◽  
H Nmr ◽  
Derivatives Of

The preparation and properties of a series of rhenium compounds of the general formula (η-C5H5)Re(CO)2XY in which X or Y or both is a silyl, germyl, or stannyl ligand are reported. The silyl hydrides cis-(η-C5H5)Re(CO)2(SiR3)H (R = Ph, CH2Ph) and cis-(η-C5H5)Re(CO)2(SiPh2H)H were obtained by ultraviolet irradiation of (η-C5H5)Re(CO)3 and the appropriate silane. The hydrides trans-(η-C5H5)Re(CO)2XH(X = SiPh3, GeCl3, GeBr3, SnCl3) were obtained by protonation of the corresponding anions. These new anions [(η-C5H5)Re(CO)2X]− also reacted with other electrophiles to yield compounds of the type trans-(η-C5H5) Re(CO)2XY (Y = Me, halogen, SnR3). The reaction of (η-C5H5)Re(CO)3 with Cl3GeH or Ph3SnH yielded only the compounds trans-(η-C5H5)Re(CO)2(GeCl3)2 and trans-(η-C5H5)Re(CO)2(SnPh3)2 respectively. Infrared and 1H nmr spectra are reported for all compounds, and v(Re–H) values for the hydrides have been obtained from Raman spectra.

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