- High-Pressure Approach to the Total Synthesis of (+/-)-Ambreinolide and (+/-)-8-Epiambreinolide
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Ambreinolide (7a) and its epimer (7b) have been synthesized regioselectively and in a stereocontrolled manner from (+/-)-trans-1,1,4aβ-trimethyldecahydronaphthalen-5-one (1) by a route (Scheme I) which relies upon the promotion of a key Diels-Alder reaction under conditions of high pressure.
- Daniewski, Wlodzimierz M.,Kubak, Elzbieta,Jurczak, Janusz
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Read Online
- A total synthesis of (±)-hispanolone
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Hispanolone (1), employed recently in our partial synthesis of the specific platelet activating factor antagonist prehispanolone (2), was prepared from (±)-Wieland-Miescher ketone (4).
- Cheung, Wing Shun,Wong, Henry N. C.
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Read Online
- Concise syntheses of (+)-austrodoral and (+)-austrodoric acid Based on H2O2 mediated oxidative ring contraction
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Asymmetric synthesis of the marine nor-sesquiterpenoid (+)-austrodoric acid and (+)-austrodoral in seven and nine steps respectively from Wieland-Miescher ketone was described herein. The synthesis featured an oxidative ring contraction of α-formyl cyclic ketone mediated by H2O2 to forge the hydrindane scaffold together with the contiguous quaternary carbon centers simultaneously.
- Wei, Hongbo,Zhang, Hongli,Han, Shoule,Mu, Shan,Huang, Ke,Chen, Guzhou,Xie, Weiqing
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supporting information
(2019/08/07)
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- Divergent Synthesis of Marine Natural Products Siphonodictyal B, Corallidictyals C/D, and Liphagal Based on the Early Presence of an Aldehyde Group Instead of a Late-Stage Introduction
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An iodine-promoted sunlight-induced olefin Z/E isomerization reaction together with a palladium-catalyzed direct cross-coupling reaction of a drimanal hydrazone and an iodobenzaldehyde, without touching the aromatic aldehyde group, facilitated a divergent and expeditious access to bioactive marine natural products siphonodictyal B, corallidictyals C/D, and liphagal based on the early presence of an aldehyde group instead of a late-stage introduction.
- Wang, Jun-Li,Li, Hui-Jing,Wu, Yan-Chao
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p. 8716 - 8723
(2018/06/11)
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- Regioselective 1,2-Diol Rearrangement by Controlling the Loading of BF3·Et2O and Its Application to the Synthesis of Related Nor-Sesquiterene- and Sesquiterene-Type Marine Natural Products
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The regiocontrolled rearrangement of 1,2-diols has been achieved by controlling the loading of BF3·Et2O. Its applicability is showcased by the divergent synthesis of austrodoral, austrodoric acid, and 8-epi-11-nordriman-9-one, as well as a formal synthesis of siphonodictyal B and liphagal. A new light is shed on piancol-type rearrangements that will be useful in diversity-oriented synthesis of related natural products.
- Wang, Jun-Li,Li, Hui-Jing,Wang, Hong-Shuang,Wu, Yan-Chao
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supporting information
p. 3811 - 3814
(2017/07/26)
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- Regiodivergent Remote Arylation of Cycloalkanols to Dysideanone′s Fused Carbotetracycles and Its Bridged Isomers
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Regiodivergent γ and γ′ arylations across an all-carbon quaternary center of cycloalkanols to access enantioenriched fused and bridged carbotetracycles are reported. The conformation of the carbocation guided either sequential stereospecific β-C-Me/γ-C?H-shifts or β-C-Me/γ′-C?H-shifts, providing fused carbotetracyclic analogs of dysideanone or bridged tetracycles, respectively. The reaction is highly stereoselective in building three contiguous stereocenters, where one, two, or three could be all-carbon quaternary centers. Interestingly, mechanistic studies revealed a crucial role of a methyl substituent in controlling regioselectivity.
- Haque, Md Ashraful,Jana, Chandan K.
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p. 13300 - 1330
(2017/09/11)
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- Synthetic method of austrodoral and austrodoric acid
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The invention relates to a synthetic method of an ocean terpene natural product austrodoral, austordoric acid and a land terpene natural product 8-epi-11-nordriman-9-one and belongs to the field of chemical synthesis. Sesquiterpenes vicinal diol is prepared by selective ozonization reaction of sesquiterpenes enol, the land terpene natural product 8-epi-11-nordriman-9-one and the ocean terpene natural product austrodoral are synthesized by the selective rearrangement reaction of the sesquiterpenes vicinal diol, and the ocean terpene natural product austrodoric acid is synthesized by oxidation reaction of the austrodoral. The method has the characteristics of low production cost, simple process conditions, easiness in control, suitability for industrial production, high overall yield and the like.
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Paragraph 0017; 0018
(2017/03/21)
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- Biomimetic Enantioselective Total Synthesis of (?)-Mycoleptodiscin A
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Biomimetic total synthesis of (?)-mycoleptodiscin A (1) was achieved starting from the enantiopure key intermediate, which was prepared by Friedel-Crafts reaction between 7-methoxyindole and chiral primary allylic alcohol. The crucial step in this synthes
- Dethe, Dattatraya H.,Sau, Susanta Kumar,Mahapatra, Samarpita
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supporting information
p. 6392 - 6395
(2016/12/23)
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- Enantioselective access to (-)-Ambrox starting from β-farnesene
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Starting from inexpensive (E)-β-farnesene (1), an eight-step enantioselective synthesis of the olfactively precious Ambrox ((-)-2a) has been performed. The crucial step is the catalytic asymmetric isomerization of (2E,6E)-N,N-diethylfarnesylamine (3) to t
- Chapuis, Christian
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p. 197 - 214
(2014/03/21)
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- Comparative study on the larvicidal activity of drimane sesquiterpenes and nordrimane compounds against drosophila melanogaster til-til
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Natural compounds from Drimys winteri Forst and derivatives exhibited larvicidal effects against Drosophila melanogaster til-til. The most active compound was isodrimenin (4). The highest lethal concentration to the larvae of D. melanogaster was 4.5 ± 0.8 mg/L. At very low concentrations drimenol (1), confertifolin (3), and drimanol (5) displayed antifeedant and larvae growth regulatory activity. The antifeedant results of nordrimanic and drimanic compounds were better in first instar larvae. The EC50 value of polygodial (2) was 60.0 ± 4.2 mg/L; of diol 15 45.0 ± 2.8 mg/L, and of diol 17 36.9 ± 3.7 mg/L, while the new nordrimane compound 12 presented a value of 83.2 ± 3.5 mg/L.
- Montenegro, Ivan,Pino, Luis,Werner, Enrique,Madrid, Alejandro,Espinoza, Luis,Moreno, Luis,Villena, Joan,Cuellar, Mauricio
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p. 4192 - 4208
(2013/06/26)
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- Synthesis of phosphatidylinositol 3-kinase (PI3K) inhibitory analogues of the sponge meroterpenoid liphagal
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Analogues of the sponge meroterpenoid liphagal (1) have been synthesized and evaluated for inhibition of PI3Kα and PI3Kα as part of a program aimed at developing new isoform-selective PI3K inhibitors. One of the analogues, compound 24, with IC50/sub
- Pereira, Alban R.,Strangman, Wendy K.,Marion, Frederic,Feldberg, Larry,Roll, Deborah,Mallon, Robert,Hollander, Irwin,Andersen, Raymond J.
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supporting information; scheme or table
p. 8523 - 8533
(2011/02/26)
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- Triphenylphosphine-iodine: An efficient reagent for the regioselective dehydration of tertiary alcohols
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Tertiary alcohols react under mild conditions with triphenylphosphine and iodine to give the most stable alkene in good yield.
- Alvarez-Manzaneda,Chahboun,Cabrera Torres,Alvarez,Alvarez-Manzaneda,Haidour,Ramos
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p. 4453 - 4455
(2007/10/03)
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- Correction of the structure of a new sesquiterpene from Cistus creticus ssp. creticus
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In an attempt to identify the structure of a sesquiterpene from Cistus creticus ssp. creticus proposed in the literature as 1,1,4a,6-tetramethyl-5- methylene-1,2,3,4,4α,5,8,8α-octahydronaphthalene, the synthesis of its cis isomer 2 was carried out in 11 steps and 9.5% yield. Comparison of the spectra of 2 and those reported earlier for the synthetic irons isomer 1 with the spectral profile of the isolated natural product indicated that the latter was not compatible with either 1 or 2. The correct structure was assigned, by detailed spectroscopic analysis of the natural product, as 6-isopropenyl-4,4a- dimethyl-1,2,3,4,4a,5,6,7-octahydronaphthalene (3).
- Hatzellis, Konstantinos,Pagona, Georgia,Spyros, Apostolos,Demetzos, Costas,Katerinopoulos, Haralambos E.
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p. 1996 - 2001
(2008/04/18)
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- Enantiospecific synthesis of 8-epipuupehedione from (R)-(-)-carvone
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An enantiospecific synthesis of the antitumor marine sponge metabolite puupehedione (2a) and its C8-epimer 2b as their methylenedioxy derivatives 8a and 8b was achieved through concomitant O-allyl deprotection and electrocyclization of 20 deriv
- Maiti, Soumen,Sengupta, Sujaya,Giri, Chandana,Achari, Basudeb,Banerjee, Asish Kr.
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p. 2389 - 2391
(2007/10/03)
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- Total synthesis of a monocyclofarnesane norsesquiterpenoid isolated from mushroom ingested by beetle: Utility of solid state Baeyer-Villiger oxidation
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Norsesquiterpenoid 1 has been synthesised starting from (S)-(+)-Wieland-Miescher ketone analogue 3 via solid state Baeyer-Villiger oxidation as a key step.
- Hagiwara, Hisahiro,Nagatomo, Hidenori,Kazayama, Shin-Ichi,Sakai, Hitoshi,Hoshi, Takashi,Suzuki, Toshio,Ando, Masayoshi
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p. 457 - 459
(2007/10/03)
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- Total syntheses of naturally occurring molecules possessing 1,7- dioxaspiro[4.4]nonane skeletons
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The syntheses of several naturally occurring molecules, namely prehispanolone, sphydrofuran, secosyrins, and syringolides are reviewed. Interestingly, these compounds are all structurally related, possessing a 1,7-dioxaspiro[4.4]nonane framework. The pivotal step in these synthetic endeavors involves the peracid oxidation of substituted 2- trimethylsilylfurans to but-2-en-4-olides. A subsequent intramolecular Michael addition procedure was also essential in the construction of the spiro skeleton. Two significant issues concerning regioselectivity and stereoselectivity are also addressed.
- Wong, Henry N. C.
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p. 1757 - 1765
(2007/10/03)
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- Total synthesis of (-)-hispanolone and an improved approach towards prehispanolone
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On the basis of the recently reported construction of (±)-hispanolone (2), the enantiomerically pure form of (-),2, employed in our partial synthesis of the specific platelet activating factor receptor antagonist prehispanolone (3), was prepared from (S)-
- Cheung, Wing Shun,Wong, Henry N. C.
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p. 11001 - 11016
(2007/10/03)
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- Sigmosceptrins A-C: New norditerpenes from a southern Australian marine sponge, Sigmosceptrella sp.
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A Sigmosceptrella sp. of sponge collected during trawling operations in the Great Australian Bight, Australia, has yielded a series of new norterpenes. These include a new bisnorditerpene, sigmosceptrin-A (5); two new norditerpenes, sigmosceptrin-B (14) and sigmosceptrin-C (15), isolated as their methyl esters (6) and (7) respectively; and an ethylated artefact, sigmosceptrin-B ethyl ester (8). Complete stereostructures were assigned to the sigmosceptrins by spectroscopic analysis, chemical degradation, derivatization, and by a single-crystal X-ray structural analysis. A biosynthetic pathway is proposed that requires a common biosynthetic precursor to both the sigmosceptrins and norterpene cyclic peroxides.
- Bassett, Sean,Ovenden, Simon P.B.,Gable, Robert W.,Capon, Robert J.
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p. 1137 - 1143
(2007/10/03)
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- Spongiaquinone Revisited: Structural and Stereochemical Studies on Marine Sesquiterpene/Quinones from a Southern Australian Marine Sponge, Spongia sp.
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A chemical investigation of a large purple sponge, Spongia sp., from the Great Australian Bight, resulted in the isolation of a new sesquiterpene/quinone (8), together with the known compounds dehydrocyclospongiaquinone-1 (4) and spongiaquinone (2).The last compound was also isolated as the potassium salt (9), this being the first recorded account of a naturally occurring marine sesquiterpene/quinone salt.The structure for (8) was assigned by detailed spectroscopic analysis.A re-investigation into the stereostructure of spongiaquinone (2) resulted in the first unambiguous assignment of absolute stereochemistry, and uncovered the peculiar chiroptical properties of spongiaquinone (2) and its potassium salt (9).
- Capon, Robert J.,Groves, Darrin R.,Urban, Sylvia,Watson, Russell G.
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p. 1245 - 1253
(2007/10/02)
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- A NEW CHIRAL ROUTE TOWARD TERPENOIDS. ANNULATION OF CARVONE TO TRANS- AND CIS-FUSED BICYCLIC SYNTHONS
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Starting from carvone, 1 two consecutive alkylations at C-6 followed by an acid-catalyzed cyclization give new bicyclic ketones which are potentially useful chirons for synthesis of terpenes such as drimanes, labdanes and triterpenes.The stereoselectivity
- Gesson, Jean-Pierre,Jacquesy, Jean-Claude,Renoux, Brigitte
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p. 5853 - 5866
(2007/10/02)
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- Chemistry of the Podocarpaceae. LVII The Preparation of Some 1,3-Dioxans with Ambergris-Type Odours
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The preparation of a series of five-, six, seven and eight-membered ring dioxa compounds is described.All posses odours of the ambra-type, the ambergris character decreasing in intensity as the size of the dioxa ring is increased.The formation of some methoxymethyl ethers is described.
- Cambie, Richard C.,Palmer, Brian D.
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p. 1265 - 1284
(2007/10/02)
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