Reaction of 18β,19β-Epoxylupan-21-one Derivatives with Acids: A Way to 21,22-Disubstituted Lup-18-ene Triterpenoids

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Title:Reaction of 18β,19β-Epoxylupan-21-one Derivatives with Acids: A Way to 21,22-Disubstituted Lup-18-ene Triterpenoids
Creators:
Klinotová, Eva
Čermáková, Jitka
Rejzek, Martin
Křeček, Václav
Sejbal, Jan
Olšovský, Petr
Klinot, Jiří
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 64, 2, pp. 329-347
Uncontrolled Keywords:NMR spectroscopy, <sup>1</sup>H and <sup>13</sup>C, Triterpenes, Epoxy ketones, Triterpenoids, Lupane

Abstract

Depending on the conditions and the acid employed, 18β,19β-epoxy-28-hydroxy- 21-oxolupan-3β-yl acetate (<strong>2a</strong>) and 18β,19β-epoxy-21-oxolupane-3β,28-diyl diacetate (<strong>2b</strong>) on treatment with acid gave three types of products: (i) 28-nor derivatives: 21-oxo-28-norlupa-16,18-dien-3β-yl acetate (<strong>6</strong>), 19β-hydroxy-21-oxo-28-norlup-17-en-3β-yl acetate (<strong>7</strong>) and 17ξ-hydroxy-21-oxo-28-norlup-18-en-3β-yl acetate (<strong>8</strong>), (ii) lupa-12,18-dien-21-ones <strong>4a</strong> and <strong>4b</strong>, and (iii) 22β-substituted lup-18-en-21-one derivatives of the type <strong>5</strong>. The formation of 22β-substituted derivatives of the type <strong>5</strong> probably proceeds in the enol form of epoxy ketone <strong>2</strong>. Opening of the epoxide ring with shift of the double bond to position 19(21) and attack by nucleophilic species at C-22 followed by elimination of water and re-formation of the 22-oxo group leads to derivatives of the type <strong>5</strong>. <p>

Title:Reaction of 18β,19β-Epoxylupan-21-one Derivatives with Acids: A Way to 21,22-Disubstituted Lup-18-ene Triterpenoids
Creators:
Klinotová, Eva
Čermáková, Jitka
Rejzek, Martin
Křeček, Václav
Sejbal, Jan
Olšovský, Petr
Klinot, Jiří
Uncontrolled Keywords:NMR spectroscopy, <sup>1</sup>H and <sup>13</sup>C, Triterpenes, Epoxy ketones, Triterpenoids, Lupane
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:64
Number:2
Page Range:pp. 329-347
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19990329UNSPECIFIED
ID Code:1480
Item Type:Article
Deposited On:06 Feb 2009 17:09
Last Modified:06 Feb 2009 16:10

Citation

Klinotová, Eva; Čermáková, Jitka; Rejzek, Martin; Křeček, Václav; Sejbal, Jan; Olšovský, Petr; Klinot, Jiří (1999) Reaction of 18β,19β-Epoxylupan-21-one Derivatives with Acids: A Way to 21,22-Disubstituted Lup-18-ene Triterpenoids. Collection of Czechoslovak Chemical Communications, 64 (2). pp. 329-347. ISSN 0010-0765

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