24179-85-9Relevant academic research and scientific papers
DRIMANE-TYPE SESQUITERPENOIDS FROM THE LIVERWORT MAKINOA CRISPATA
Hashimoto, Toshihiro,Tori, Motoo,Asakawa, Yoshinori
, p. 3377 - 3382 (1989)
Three new drimane-type sesquiterpenoids, 7α-chloro-6β-hydroxyconfertifoline, 6β,7α-dihydroxyconfertifoline and 6β,7β-epoxyconfertifoline were isolated from the liverwort Makinoa crispata together with the previously known eudesmane-type sesquiterpene lactone, crispatanolide and a sacculatane-type diterpene dialdehyde, perrottetianal A.The stereostructures of the new compounds were established by 2D NMR and CD spectroscopy and chemical evidence.The present chemical results support Schuster's phylogenic classification of the two orders, Metzgeriales and Jungermanniales.Key Word Index - Makinoa crispata; Metzgeriales; Hepaticae; crispatanolide; 7α-chloro-6β-hydroxyconfertifoline; 6β,7α-dihydroxyconfertifoline; 6β,7β-epoxyconfertifoline; drimane-type sesquiterpenoid; chemosystematics.
Synthesis of (+)-fragolide and (-)-pereniporin B via vinylsilane terminated cationic cyclization
Burke, Steven D.,Shankaran,Helber, Margaret Jones
, p. 4655 - 4658 (2007/10/02)
Enantioselective syntheses of (+)-fragolide and (-)-pereniporin B are detailed. Marino's lactone annulation method was employed to establish relative and absolute stereochemistry at carbon in the bicyclization substrate. Regio- and stereoselective oxidati
Synthesis of Mono- and Sesquiterpenoids, XVI - Synthesis of (-)-Pereniporins A and B, Sesquiterpene Antibiotics from a Basidiomycete
Mori, Kenji,Takaishi, Hideo
, p. 939 - 944 (2007/10/02)
Starting from (S)-3-hydroxy-2,2-dimethyl-1-cyclohexanone (5), the enantioselective total syntheses of (-)-pereniporins A (1) and B (2) were achieved in 33 steps (0.6percent overall yield) and in 28 steps (1.8percent overall yield), respectively.
Syntheses of the Insect Antifeedant (+/-)-Cinnamodial and the Drimane Sesquiterpenoids (+/-)-Isodrimenin and (+/-)-Fragrolide
White, James D.,Burton, Lester P.J.
, p. 357 - 364 (2007/10/02)
Total syntheses of (+/-)-cinnamodial (5), (+/-)-isodrimenin (24), and (+/-)-fragrolide (29) are described begining from the diene 7.Hydroboration-oxidation of 7 gave the trans-fused alcohol 18, and elimination of mesylate 21, followed by selective reduction at the more accesible ester function, led to γ-lactone 23, which afforded 24 upon hydrogenation.A different route from 18 produced triol 27, which was selectively oxidized at the more exposed primary alcohol to yield γ-lactone 28.The latter, upon oxidation, furnished 29.The synthesis of 5 hinged upon the construction of furan 38 , which was obtained from lactone 26 via 37 or, directly, by oxidation of 27.Oxidation of 38 with lead tetraacetate gave 41, which underwent elimination with DBU to provide 43.Regio- and stereoselective epoxidation of this dienone gave 45 which, upon acidic methanolysis, led to 50.Reduction of this ketone resulted in the 6β alcohol 51, and exposure of this bis acetal to acid released the dialdehyde array of 52.Finally, acetylation of 52 gave 5.
SYNTHESES OF OPTICALLY ACTIVE (+)-FRAGROLIDE AND (+)-BEMADIENOLIDE FROM DEHYDROABIETIC ACID
Akita, Hiroyuki,Anazawa, Akira,Oishi, Takeshi
, p. 1588 - 1593 (2007/10/02)
14-Hydroxydehydroabietane derivatives (8 and 9), having an oxygen functional group at the 6-position, were obtained from 14-hydroxy-7-oxodehydroabietane (10) by transformation of the 7-oxo group into a 6-acetoxyl (or hydroxyl) group.Ozonolysis of the above phenols (8 and 9) and subsequent reduction gave the 6-oxygenated confertifolin derivatives 17 and 19, respectively.Oxidation of 6-hydroxyconfertifolin (19) afforded the optically active (+)-fragrolide (4).On the other hand, 19 was also converted into (+)-bemadienolide (5) by oxidation of the important intermediate, 6β-phenylselenoconfertifolin (25).Keywords: - aromatic ring cleavage; drimanic sesquiterpenes; phenolic diterpenes; ozonolysis; transfer of ketone
