Beckmann rearrangement of oxime obtained from oleanolic acid. Structure elucidation of the initial oxime

2013 ◽  
Vol 1053 ◽  
pp. 115-121 ◽  
Author(s):  
Barbara Bednarczyk-Cwynar ◽  
Lucjusz Zaprutko ◽  
Anna Froelich
Keyword(s):  
Oleanolic Acid ◽  
Structure Elucidation ◽  
Beckmann Rearrangement ◽  
Acid Structure

scholarly journals C-Lactam Derivatives of Oleanolic Acid. The Synthesis of C-lactam by Beckmann Rearrangement of C-oxime

2011 ◽  
Vol 6 (12) ◽  
pp. 1934578X1100601
Author(s):  
Barbara Bednarczyk – Cwynar
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Oleanolic Acid ◽  
Structure Elucidation ◽  
Beckmann Rearrangement ◽  
Hydroxyl Group ◽  
Chemical Transformations ◽  
Group A ◽  
Derivatives Of ◽  
Carbonyl Function

Oleanolic acid, one of the most known triterpenes, was subjected to different chemical transformations within C-3 β-hydroxyl group, a double bond between C-12 and C-13, and a carboxyl function at C-17 in order to obtain new derivatives. The key compound consists of four six-membered rings (A, B, D, E) and one enlarged ring (C ring) containing a nitrogen atom and a carbonyl function – lactam. This type of derivative can be obtained by Beckmann rearrangement of the appropriate oxime. The lactam can be transformed into thiolactam with the use of Lavesson's reagent. The method is also presented for new derivatives synthesis, as well as their structure elucidation by spectroscopic means.

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.

Identification of Potent Odorants Formed by Autoxidation of Arachidonic Acid:  Structure Elucidation and Synthesis of (E,Z,Z)-2,4,7-Tridecatrienal

2001 ◽  
Vol 49 (6) ◽  
pp. 2959-2965 ◽  
Author(s):  
Imre Blank ◽  
Jianming Lin ◽  
Francia Arce Vera ◽  
Dieter H. Welti ◽  
Laurent B. Fay
Keyword(s):  
Arachidonic Acid ◽  
Structure Elucidation ◽  
Potent Odorants ◽  
Acid Structure

Oleanolic acid rich solubilized triterpene extracts from mistletoe induce apoptotic and necrotic cell death of murine B16. F10 melanoma cells

Planta Medica ◽  
2009 ◽  
Vol 75 (09) ◽  
Author(s):  
CM Strüh ◽  
S Jäger ◽  
CM Schempp ◽  
T Jakob ◽  
A Scheffler ◽  
...  
Keyword(s):  
Cell Death ◽  
Oleanolic Acid ◽  
Melanoma Cells ◽  
Necrotic Cell Death ◽  
Necrotic Cell
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