- Synthesis of trans-β-Elemene
-
Highly efficient syntheses of the anti-cancer agent trans-β-elemene have been achieved by using the readily available (±)-limonene as starting material. The syntheses were achieved in only nine to eleven steps with good overall yields. The key step in these reaction sequences is a stereoselective radical cyclization, induced by titanocene chloride.
- Benito Iglesias,Herrero Teijón,Rubio González, Rosa,Fernández-Mateos
-
p. 4926 - 4932
(2018/09/11)
-
- Isogermacrene A, a proposed intermediate in sesquiterpene biosynthesis
-
A sesquiterpene hydrocarbon, isogermacrene A (5), which is structurally related to the gorgonanes and zieranes, was isolated from the essential oil of Saccogyna viticulosa (Hepaticae). This monocyclic compound is proposed as the biogenetic intermediate of some rare sequiterpene skeletons. In the essential oil of the liverwort Saccogyna viticulosa, collected on the island of Madeira, the new sesquiterpene hydrocarbons isogermacrene A (5) and its Cope rearrangement product iso-β-elemene (6) were identified. 5 is proposed to act as the biogenetic precursor of several new sesquiterpenes identified in the volatiles of S. viticulosa. These include iso-α-humulene, α-gorgonene, gorgona-1,4(15),11-triene and gorgon-11-en-4-ol. In addition, the Cope product of zierene, isozierene, allo-aromadendra-4(15),10(14)-diene, aromadendra-4(15),10(14)-dien-1-ol and a prenylguaiane diterpene alcohol, named viticulol, were identified as new natural products.
- Hackl, Thomas,K?nig, Wilfried A.,Muhle, Hermann
-
p. 2261 - 2275
(2007/10/03)
-
- Stereoselective synthesis of (±)-β-elemene by a doubly diastereodifferentiating internal alkylation: A remarkable difference in the rate of enolization between syn and anti esters
-
A total synthesis of the sesquiterpene (±)-β-elemene (1) has been achieved starting from a simple acyclic precursor 4. Key transformations include a 'doubly diastereodifferentiating folding and allylic strain-controlled' intramolecular ester enolate alkylation. In the course of the synthesis, we encountered remarkably different reactivity between syn and anti diastereomeric esters in the enolization step.
- Kim, Deukjoon,Lee, Jongkook,Chang, Jiyoung,Kim, Sanghee
-
p. 1247 - 1252
(2007/10/03)
-
- Enantioselective total synthesis of β-elemene and fuscol based on enantiocontrolled Ireland-Claisen rearrangement
-
The potent antiinflammatory agent precursor (+)-fuscol (2) has been synthesized using the chiral reagent 1 to effect the key step, the completely enantioselective Ireland-Claisen rearrangement of ester 3 to acid 4a. Conversion of 4a to the corresponding aldehyde 4c, cation-olefin cyclization to 5a, and deoxygenation produced (+)-β-elemene (6). (+)-Fuscol (2) was synthesized from 6 via intermediates 7 and 8.
- Corey,Roberts, Bryan E.,Dixon, Brian R.
-
p. 193 - 196
(2007/10/02)
-
- SYNTHESIS OF HELMINTHOGERMACRENE AND β-ELEMENE
-
Helminthogermacrene (1) and β-elemene (3) have been synthesized by a short route starting from geranylacetone.Titanium-induced cyclization of 3-isopropenyl-6-methyl-10-oxo-6E-undecenal (7) was used as the key step.
- McMurry, John E.,Kocovsky, Pavel
-
p. 2171 - 2172
(2007/10/02)
-