Unusual ozonolysis pattern for 28-oxo-2,3-indoloallobetulin

Казакова, О. Б.; Khusnutdinova, É. F.; Лобов, А. Н.; Zvereva, T. I.; Legostaeva, Yu. V.; Толстиков, Г. А.; Khrustalev, Victor N.

doi:10.1007/s11172-011-0267-8

Cited by 10 publications

(4 citation statements)

References 2 publications

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“…12). An unusual reaction with ozone for the preparation of hydroxyquinoline 324 from indole 37 was published 58 (Scheme 20). The mechanism of this reaction is based on the formation of molozonide on the A-ring of the triterpene followed by release of hydrogen peroxide and A-ring rearrangement.…”

Section: Pyridine and Quinolone Derivativesmentioning

confidence: 99%

Pentacyclic triterpenoids with nitrogen- and sulfur-containing heterocycles: synthesis and medicinal significance

et al. 2015

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Triterpenoids are natural compounds with a variety of biological activities and are usually produced by plants as secondary metabolites. In recent decades, scientists focused on the properties of triterpenoids have discovered many activities, such as antitumor, antiviral, antimicrobial, anti-inflammatory and others. Thousands of new triterpenoids with various skeletal modifications have now been synthesized. One of the most important modifications is the formation of a new heterocyclic ring. The simple fact that the vast majority of currently used drugs are heterocyclic compounds has encouraged a lot of researches to synthesize analogous triterpenoid derivatives in order to find new molecules with higher activities and consequently optimize their pharmacological profile. The biological properties of triterpenoid heterocycles are very promising and many of them have been studied, especially as antitumor agents. This review is mainly focused on the synthesis of various types of nitrogen and occasionally sulfur-containing heterocyclic triterpenoids for their potential use as future drugs in medicine and in addition discusses their overall biological activities.

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Section: Pyridine and Quinolone Derivativesmentioning

confidence: 99%

Pentacyclic triterpenoids with nitrogen- and sulfur-containing heterocycles: synthesis and medicinal significance

et al. 2015

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“…We suppose that the formation of quinolones 2 and 5 occurs by standard 1,3-dipolar cycloaddition of ozone to the С2-С3 double bond of indole 1 [22]. On the other hand, the probable way of spiro derivatives formation is based on 1,2-cycloaddition of ozone to the С2-С3 double bond of indole 1 followed by intramolecular rearrangements of 2,3-epoxy-intermediate to3 and 4.…”

mentioning

confidence: 99%

Synthesis of new A-conjugated Quinolone and Spiroindole Dammaranes by the Ozonolysis of 2,3-Indolodipterocarpol

Смирнова

Khusnutdinova

Лобов

et al. 2018

Natural Product Communications

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An one-step and efficient access to the new dammarane A-quinolones by ozonolysis of 2,3-indolodipterocarpol at 0°C through the 1,3-dipolar cycloaddition of ozone to the С2-С3 double bond of the triterpenoid core is reported. In the case of oxidation in AcOH, two spiroindoles were identified as a result of 1,2cycloaddition of ozone to the С2-С3 double bond with following intramolecular rearrangements of 2,3-epoxy-intermediate. The structures of four new compounds were established by 1H, 13C NMR, COSY, NOSY, HMBC and HSQC analyses.

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“…We previously reported the synthesis of di-and triterpenoids and steroids with 1,2,4-trioxolane [13][14][15], 1,2,4,5-tetraoxane [16,17], epoxide [18,19], oxetane [20], lactone [21], quinolone [22] fragments. Herein, we report the stereospecific oxidation of diacetoxyheterobetulin 1 with ozone and dimethyldioxirane.…”

mentioning

confidence: 99%

Stereospecific Oxidation of Diacetoxyheterobetulin with Ozone and Dimethyldioxirane

Khusnutdinova

Medvedeva

Казаков

et al. 2016

Natural Product Communications

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Stereospecific oxidation of diacetoxyheterobetulin with ozone and dimethyldioxirane led to 3,28-diacetoxy-18α,19βH-urs-20α,21α-epoxide with yields of 79% and 87%, respectively. Oxidation with ozone was not selective and gave two minor products containing 21α-hydroxy-20(30)-ene and 21α-hydroxy-20β,28-epoxy-fragments in ring E. The structures of 3,28-diacetoxy-18α,19βH-urs-20α,21α-epoxide and 3β-diacetoxy-21α-hydroxy-20β,28-epoxy-18α,19βH-ursane were confirmed by X-ray analysis for the first time.

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Unusual ozonolysis pattern for 28-oxo-2,3-indoloallobetulin

Cited by 10 publications

References 2 publications

Pentacyclic triterpenoids with nitrogen- and sulfur-containing heterocycles: synthesis and medicinal significance

Pentacyclic triterpenoids with nitrogen- and sulfur-containing heterocycles: synthesis and medicinal significance

Synthesis of new A-conjugated Quinolone and Spiroindole Dammaranes by the Ozonolysis of 2,3-Indolodipterocarpol

Stereospecific Oxidation of Diacetoxyheterobetulin with Ozone and Dimethyldioxirane

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