Cyclization of 17-ethylenedioxy-3α,5-cyclo-6,7-seco-5α-androstane-6,7-diol

1979 ◽  
Vol 44 (1) ◽  
pp. 128-144 ◽  
Author(s):  
Helena Velgová ◽  
Dietrich Zeigan ◽  
Günther Engelhardt ◽  
Antonín Trka
Keyword(s):  
Acetic Anhydride ◽  
Intramolecular Cyclization ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Mass Spectrometric ◽  
Cyclic Ethers ◽  
Mass Spectrometric Data ◽  
Spectrometric Data ◽  
H Nmr ◽  
C Nmr

Intramolecular cyclization of 17-ethylenedioxy-3α,5-cyclo-6,7-seco-5α-androstane-6,7-diol (I) on treatment with p-toluenesulphonyl chloride in pyridine gives 17-ethylenedioxy-3α,5-cyclo-B-homo-7-oxa-5α-androstane (III) and 17-ethylenedioxy-3,5-methylene-6-oxaandrostane (II). The cyclic ethers II and III after deketalization and treatment with boron trifluoride etherate in acetic anhydride yield 3β,7-dihydroxy-6,7-secoandrost-5-en-17-one (XIV) along with a small quantity of 3β,5-cyclo-A-homo-6-oxa-5β-androstane-17-one (XIII). Proof of the structures in question is based on IR, 1H NMR, 13C NMR and mass spectrometric data.

scholarly journals Melitidin: A Flavanone Glycoside from Citrus grandis ‘Tomentosa’

2013 ◽  
Vol 8 (4) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Wei Zou ◽  
Yonggang Wang ◽  
Haibin Liu ◽  
Yulong Luo ◽  
Si Chen ◽  
...  
Keyword(s):  
Citric Acid ◽  
Chinese Medicine ◽  
Mass Spectrometric ◽  
Mass Spectrometric Data ◽  
Spectrometric Data ◽  
Antitussive Effect ◽  
First Time ◽  
Flavanone Glycoside ◽  
Resolution Mass ◽  
C Nmr

Citrus grandis ‘Tomentosa’ is a traditional Chinese medicine, used as an antitussive. In this research, melitidin, a flavanone glycoside, was isolated from this species for the first time by using chromatographic methods. The structure was confirmed through comprehensive analyses of its ultraviolet, infrared, 1H and 13C NMR, HMBC and HMQC spectroscopic and high-resolution mass spectrometric data. Meliditin showed a good antitussive effect on cough induced by citric acid in Guinea pig, suggesting that it was a contributor to the antitussive effect of C. grandis ‘Tomentosa’.

C-Lactam Derivatives of Oleanolic Acid. Hydrolysis and Further Acylation of Methyl Acetyloleanolate C-Lactam and C-Thiolactam

2014 ◽  
Vol 9 (3) ◽  
pp. 1934578X1400900
Author(s):  
Barbara Bednarczyk–Cwynar ◽  
Lucjusz Zaprutko
Keyword(s):  
Acetic Anhydride ◽  
Acid Hydrolysis ◽  
Oleanolic Acid ◽  
Alkaline Hydrolysis ◽  
Beckmann Rearrangement ◽  
Mass Spectrometric ◽  
Hydroxyl Group ◽  
Mass Spectrometric Data ◽  
Spectrometric Data ◽  
Derivatives Of

Acetyl methyl oleanolate was transformed into a seven-membered C-lactam derivative (2) using Beckmann rearrangement of the corresponding C-oxime during the last step of the synthesis. The C=O group of the lactam system was transformed into a C=S group by Lavesson's reagent. The resulting acetylthiolactam 3 and initial acetyllactam 2 were subjected to alkaline hydrolysis to obtain lactam 4 and thiolactam 5 with an unsubstituted C-3 hydroxyl group. Subsequently, compounds 4 and 5 were acylated with either succinic or acetic anhydride in pyridine. Various acylating conditions were tested for hydroxythiolactam 5. The structures of the newly obtained compounds were supported by spectral and mass spectrometric data.

scholarly journals Stereochemistry and NMR Data Assignment of Cyclopeptide Alkaloids from Zizyphus Oxyphylla

2010 ◽  
Vol 5 (8) ◽  
pp. 1934578X1000500
Author(s):  
Muhammad Nisar ◽  
Waqar Ahmad Kaleem ◽  
Achyut Adhikari ◽  
Zulfiqar Ali ◽  
Nusrat Hussain ◽  
...  
Keyword(s):  
Spectroscopic Data ◽  
Mass Spectrometric ◽  
Mass Spectrometric Data ◽  
Spectrometric Data ◽  
Nmr Data ◽  
Cyclopeptide Alkaloids ◽  
First Time ◽  
C Nmr

The structures of (3 S,7 R,13 S)-6-[2-(dimethylamino)-3-phenylpropanoyl]-19-methoxy-2-oxa-6,9,15-triazatetracyclo[16.3.1.03,7. 09,13]docosa-1-(22),16,18,20-tetraene-8,14-dione (1), nummularin-C (2) and nummularin-R (3) have been previously determined mainly based on mass spectrometric data. Stereochemistry and complete 1H and 13C NMR spectroscopic data assignments of these compounds are now described. Compounds 1 and 2 are reported for the first time from

Application of Factor Analysis in Imaging Mass Spectrometric Data Analysis

2014 ◽  
Vol 42 (8) ◽  
pp. 1099-1103 ◽  
Author(s):  
Yi CHEN ◽  
Fei TANG ◽  
Tie-Gang LI ◽  
Jiu-Ming HE ◽  
Zeper ABLIZ ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Data Analysis ◽  
Mass Spectrometric ◽  
Mass Spectrometric Data ◽  
Spectrometric Data
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