Further Synthetic Studies Towards the Austrodorane Skeleton: Synthesis of Austrodoral

Kulciţki, Veaceslav; Ungur, Nicon; Gavagnin, Margherita; Carbone, Marianna; Cimino, Guido

doi:10.1002/ejoc.200400795

Cited by 37 publications

(11 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Allylic oxidation applying Nhydroxysuccinimide/Na 2 Cr 2 O 7 in acetone furnished the 11-keto-derivatives 10 and 11, respectively. Elimination reaction of 10 under Mitsunobu conditions [25,26] afforded the alkene 13, whereas from 11 compound 14 was obtained. Finally, reaction of 13 with sodium dichromate in the presence of sodium dichromate furnished the endoperoxide 15.…”

Section: Resultsmentioning

confidence: 95%

Antitumoractive Endoperoxides from Triterpenes

Niesen

Barthel

Kluge

et al. 2009

Archiv der Pharmazie

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 95%

Antitumoractive Endoperoxides from Triterpenes

Niesen

Barthel

Kluge

et al. 2009

Archiv der Pharmazie

View full text Add to dashboard Cite

show abstract

“…616 Two groups have reported the stereoselective synthesis of the nor-sesquiterpene (+)-austrodoral 780, originally isolated from the Antarctic nudibranch Austrodoris kerguelenensis, 617 starting from either (−)-sclareol 618 or (+)-sclareolide. 619 Furanosesquiterpenes alcohols pelseneeriols-1 781 and -2 782 were isolated from the mantle of the nudibranch Doriopsilla pelseneeri (Portugal). 469 Syntheses of 5-methyl-2-((2E,6E)-3,7,11-trimethyl-2,6-dodecadien-9-onyl)benzo-1,4-quinone and the hydroquinone, isolated from the South African nudibranch Leminda millecra, 620 have been reported.…”

Section: Molluscsmentioning

confidence: 99%

Marine natural products

Blunt¹,

Copp²,

Hu³

et al. 2007

Nat. Prod. Rep.

468

288

View full text Add to dashboard Cite

This review covers the literature published in 2005 for marine natural products, with 704 citations (493 for the period January to December 2005) referring to compounds isolated from marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, coelenterates, bryozoans, molluscs, tunicates and echinoderms. The emphasis is on new compounds (812 for 2005), together with their relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.

show abstract

“…Norambreinolide (10) was converted by the literature method [14,15] in six steps into iso-drimenol (11).…”

Section: Methodsmentioning

confidence: 99%

“…A solution of phosphorus tribromide (653 mg, 1.78 mmol) in dry ether (0.5 mL) was added dropwise to a stirred solution of bicyclic alcohol 11 (395 mg, 1.78 mmol) [15] in dry ether (3.1 mL) and pyridine (0.2 mL) with cooling on an ice bath and then stirred for 2 h at room temperature. The usual work up afforded crude bromide 12 (486.8 mg, 96%), which was used in the following step without further purification.…”

Section: Synthesis Of 8-phenylsulfonylgeraniol (4)mentioning

confidence: 99%

Superacid cyclization of (2E,6E,10E,14E)-8-phenylsulfonylgeranylfarnesol tetrahydropyranyl ether

et al. 2007

View full text Add to dashboard Cite

A mixture of (13E,17E)-12-phenylsulfonylbicyclogeranylfarnesol tetrahydropyranyl ether (8) and (13E,17E)-12-phenylsulfonylbicyclogeranylfarnesol (9) was formed by superacid low-temperature cyclization of exclusively trans-8-phenylsulfonylgeranylfarnesol tetrahydropyranyl ether (1). The structures of 8 and 9 were established using spectral data. The optically active form of 9 was also confirmed by retrosynthesis from (+)-sclareolide (10).Biomimetic superacid cyclization of terpenoids turned out to be an effective synthetic method for cyclic terpenoids [1][2][3][4][5][6][7][8]. We studied previously superacid cyclization of several α,ω-bifunctionalized mono-and sesquiterpenoids and showed that α,ω-geraniol derivatives gave cyclic products with the n-menthane structure [9] whereas α,ω-bifunctionalized sesquiterpenoids produced monocyclic derivatives of α-cyclogeraniol prenylated at the gem-dimethyl group, which were formed by initiation of the cyclization by protonation of the inner C-6-C-7 double bond [10]. Superacid cyclization of α,ω-bifunctionalized aliphatic (2E,6E,10E)-diterpenoids also begins with protonation of the inner C-10-C-11 double bond to form diterpenoids with the sacculatane carbon skeleton [11].Herein we report the synthesis and superacid cyclization of the tetrahydropyranyl (THP) ether of the bifunctionalized derivative of exlusively trans-geranylfarnesol in which the second functional group, phenylsulfonyl, is located in the middle of the aliphatic carbon chain of the sesquiterpenoid on C-8. We selected the phenylsulfonyl group because it is easy to insert in the necessary position on the carbon chain, is stable toward superacid, and can be replaced by other functional groups.The starting material for cyclization of the THP ether of exclusively trans-8-phenylsulfonylgeranylfarnesol (1) was prepared by etherification of exclusively trans-8-phenylsulfonylgeranylfarnesol (2) with dihydropyran (90% yield). Compound 2, in turn, was synthesized in 91% yield by addition of commercially available (2E,6E)-farnesylchloride (3) to 8-phenylsulfonylgeraniol (4), which was prepared from the known ω-hydroxygeranylacetate (5) [12]. Bromination of the last by phosphorus tribromide produced 8-bromogeranylacetate (6) in 70% yield. This reacted smoothly with sodium phenylsulfonate to give 8-phenylsulfonylgeranylacetate (7). Saponification of 7 with alcoholic base gave 8-phenylsulfonylgeraniol (4) (Scheme 1).Spectral and elemental analysis were used to find the structure of 2. Its PMR spectrum contained signals for 6 methyls on double bonds, 5 vinyl protons, and >C=CHCH 2 OH and >CHSO 2 Ph groups. Its 13 C NMR spectrum exhibited signals for 6 methyls on fully substituted C atoms, 8 methylenes, and 11 methines, 6 fully substituted C atoms, and 16 sp 2 -hybridized C atoms. Superacid cyclization of the THP ether of 1 by fluorosulfonic acid at -78°C in 2-nitropropane formed a mixture of compounds, from which column chromatography over silica gel isolated two pure compounds of different polarity. The PMR spectrum of the ...

show abstract

Further Synthetic Studies Towards the Austrodorane Skeleton: Synthesis of Austrodoral

Cited by 37 publications

References 20 publications

Antitumoractive Endoperoxides from Triterpenes

Antitumoractive Endoperoxides from Triterpenes

Marine natural products

Superacid cyclization of (2E,6E,10E,14E)-8-phenylsulfonylgeranylfarnesol tetrahydropyranyl ether

Contact Info

Product

Resources

About