11,13-Methylenation of sesquiterpene exomethylene-γ-lactones: Synthesis of sesquiterpene cyclopropyl-γ-lactones

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Title:11,13-Methylenation of sesquiterpene exomethylene-γ-lactones: Synthesis of sesquiterpene cyclopropyl-γ-lactones
Creators:
Appendino, Giovanni
Ghilardi, Elisabetta
Cravotto, Giancarlo
Gariboldi, Pierluigi
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 56, 5, pp. 1052-1063

Abstract

11,13-Methylene derivatives of sesquiterpene exomethylene-γ-lactones were prepared by reaction of diazomethane and photolysis of the resulting pyrazoline adduct(s). Variable amounts of exomethylene- and ethylidene-γ-lactones were also formed in the photolysis reaction. These compounds could bee removed after reaction with diethylamine and chromatography on a bilayer (basic alumina/silica gel) column. Also 11,13-methylene derivatives of acid-and thermolabile germacranolides could be prepared in good yield with this procedure. Results obtained using alternative methods of methylenation are reported. A comparative study of the reactivity towards nucleophiles of exomethylene- and cyclopropyl sesquiterpene-γ-lactones provided little support for the involvement of compounds of the latter class in in vivo alkylation reactions.

Title:11,13-Methylenation of sesquiterpene exomethylene-γ-lactones: Synthesis of sesquiterpene cyclopropyl-γ-lactones
Creators:
Appendino, Giovanni
Ghilardi, Elisabetta
Cravotto, Giancarlo
Gariboldi, Pierluigi
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:56
Number:5
Page Range:pp. 1052-1063
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19911052UNSPECIFIED
ID Code:5023
Item Type:Article
Deposited On:22 Feb 2010 11:28
Last Modified:22 Feb 2010 10:29

Citation

Appendino, Giovanni; Ghilardi, Elisabetta; Cravotto, Giancarlo; Gariboldi, Pierluigi (1991) 11,13-Methylenation of sesquiterpene exomethylene-γ-lactones: Synthesis of sesquiterpene cyclopropyl-γ-lactones. Collection of Czechoslovak Chemical Communications, 56 (5). pp. 1052-1063. ISSN 0010-0765

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