Structural biochemistry. IV. 3β-Hydroxy-17β-(l-prolyl)amino-androst-5-ene

1967 ◽  
Vol 45 (5) ◽  
pp. 501-507 ◽  
Author(s):  
G. R. Pettit ◽  
R. L. Smith ◽  
A. K. Das Gupta ◽  
J. L. Occolowitz
Keyword(s):  
Protecting Group ◽  
Mass Spectral ◽  
System A ◽  
Selective Reaction ◽  
Woodward’S Reagent K ◽  
Configurational Assignment ◽  
Mass Spectral Study ◽  
Palladium Catalyzed ◽  
Structural Biochemistry ◽  
Combination Of Methods

The synthesis of the title compound III was studied in detail and the following combination of methods was found reliable and convenient. The oxime derivative Ib of ketone la was reduced with sodium–ethanol to 3β-hydroxy-17β-amino-androst-5-ene. The configurational assignment for amine IIa was supported by the results of a comparison with the 17α-epimer and by a proton magnetic resonance study of both isomers. Selective reaction between amine IIa and carbobenzoxy-l-proline was achieved with Woodward's reagent K. Of several procedures explored for removing the carbobenzoxy protecting group from amide IIc, palladium-catalyzed hydrogenolysis proved quite satisfactory. Hydrogenolysis of carbamate IIb to yield prolyl amide III was realized without affecting the Δ5 olefin system. A mass spectral study of amine III and the corresponding 5α-derivative IV confirmed the latter observation. A brief review of procedures for the synthesis of steroidal amines was also presented.

STRUCTURAL BIOCHEMISTRY: II. SYNTHESIS OF 3β-HYDROXY-17β (L-PROLYL-L-PROLYL)AMINO-5α-ANDROSTANE

1966 ◽  
Vol 44 (17) ◽  
pp. 2023-2029 ◽  
Author(s):  
George R. Pettit ◽  
Arun K. Das Gupta ◽  
Robert L. Smith
Keyword(s):  
Magnetic Resonance ◽  
Hydroxy Group ◽  
Proton Magnetic Resonance ◽  
Protecting Group ◽  
Synthetic Route ◽  
Magnetic Resonance Studies ◽  
Woodward’S Reagent K ◽  
Palladium Catalyzed ◽  
Structural Biochemistry

A practical synthetic route to 3β-hydroxy-17β-amino-5α-androstane (III) was developed and the configuration of the amine substituent established by proton magnetic resonance studies. Condensing amine III with carbobenzoxy-L-proline by means of Woodward's reagent K led to proline derivative IVa. Steroidal peptide Vb was readily prepared by first removing the protecting group from amide IVa by palladium-catalyzed hydrogenolysis and then repeating the peptide-forming and hydrogenation steps. Protection of the 3β-hydroxy group proved to be unnecessary, and the presently reported approach to steroidal peptides proved to be reliable and useful.

Synthesis of Novel Bis-pyrazoles via Electrophilic Cyclization

2019 ◽  
Vol 16 (6) ◽  
pp. 511-516
Author(s):  
Adnan Cetin
Keyword(s):  
13C Nmr ◽  
Cyclization Reaction ◽  
Electrophilic Cyclization ◽  
Pyrazole Derivatives ◽  
Spectral Analyses ◽  
Mass Spectral ◽  
Palladium Catalyzed ◽  
Ft Ir ◽  
Reaction Compound

Efficient steps towards the synthesis of novel (phenyl)(1'-aryl-1,5,5'-triphenyl[3,3'-bi-1Hpyrazol]- 4-yl)methanones 4a-e were developed. The procedure starts from 1-(4-benzoyl-1,5-diphenyl- 1H-3-pyrazolyl)-3-phenyl-2-propyn-1-one (2) which was synthesized by a palladium catalyzed crosscoupling reaction. Compound 2 reacted with various hydrazines to give (E)-(phenyl)[1,5-diphenyl-3- [3-phenyl-1-(2-arylhydrazono)-2-propyn-1-yl]-1H-4-pyrazolyl]methanones E-3a-e. The bis-pyrazole derivatives 4a-e were synthesized from electrophilic cyclization reaction of α,β-acetylenic hydrazones E-3a-e and copper(I) iodide. All synthesized compounds were characterized by FT-IR, 1H, 13C NMR and Mass spectral analyses.

Fast atom bombardment mass spectral study of tetracycline antibiotics

1993 ◽  
Vol 28 (12) ◽  
pp. 1512-1515 ◽  
Author(s):  
Ken-Ichi Harada ◽  
Katsuyoshi Masuda ◽  
Makoto Suzuki ◽  
Hisao Oka ◽  
Yoshitomo Ikai ◽  
...  
Keyword(s):  
Spectral Study ◽  
Fast Atom Bombardment ◽  
Tetracycline Antibiotics ◽  
Mass Spectral ◽  
Mass Spectral Study

The alkoxides of zirconium and hafnium: direct electrochemical synthesis and mass-spectral study. Do ?M(OR)4?, where M=Zr, Hf, Sn, really exist?

1995 ◽  
Vol 44 (4) ◽  
pp. 734-742 ◽  
Author(s):  
E. P. Turevskaya ◽  
N. I. Kozlova ◽  
N. Ya. Turova ◽  
A. L. Belokon' ◽  
D. V. Berdyev ◽  
...  
Keyword(s):  
Electrochemical Synthesis ◽  
Spectral Study ◽  
Mass Spectral ◽  
Mass Spectral Study

ChemInform Abstract: Formyl Substituent at C-4 of Pyrazoles: A Temporary Protecting Group for Regioselective Palladium-Catalyzed Direct Arylation at C-5.

ChemInform ◽  
2015 ◽  
Vol 46 (4) ◽  
pp. no-no
Author(s):  
Imen Smari ◽  
Chiraz Youssef ◽  
Kedong Yuan ◽  
Anissa Beladhria ◽  
Hamed Ben Ammar ◽  
...  
Keyword(s):  
Protecting Group ◽  
Direct Arylation ◽  
Palladium Catalyzed

A General and Simple Removal of the Allyloxycarbonyl Protecting Group by Palladium-Catalyzed Reactions Using Nitrogen and Sulfur Nucleophiles

Synlett ◽  
1993 ◽  
Vol 1993 (09) ◽  
pp. 680-682 ◽  
Author(s):  
Jean Pierre Genêt ◽  
Errol Blart ◽  
Monique Savignac ◽  
Stéphane Lemeune ◽  
Sandrine Lemaire-Audoire ◽  
...  
Keyword(s):  
Protecting Group ◽  
Palladium Catalyzed ◽  
Catalyzed Reactions
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