5β(H)-Austricin, a New Guaianolide from Artemisia leucodes

A new sesquiterpene lactone 5(H)-austricin was isolated from white wormwood (Artemisia leucodes Schrenk.). Its structure was established by chemical and spectral methods.     

9β-hydroxy-11β(H),13-dihyhdrosantamarine, a new eudesmanolide fromArtemisia leucotricha

A new sesquiterpene lactone, 9-hydroxy-11(H),13-dihydrosantamarine, and known terpenes are isolated from the underground part ofArtemisia leucotricha Krasch ex Ladyg (Asteraceae). The structure is determined by spectral and x-ray structural analysis.Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 230–232, May–June, 2000.     

Artselenin, a New Guaianolide from Artemisia selengensis

Anewguaianolide,artSelenin,was0btainedfromAItemisiaseIengenSisTurcz(Compositae),anditSstIuctllrewaselucidatCdtObe2twdroXy-1cr,1od-epoXymatricdriCompound1wasobtainedascolorlesspowders,mp165-166C;[cr].20:-92(MesCO,c0.1).TheIRspectrumshowedabsorphonbandscorresp0ndingtohydroXyl(346Ocm-'),y-lactone(178Ocm-'),acetoxyl(1735,l037cm-'),doublebond(1631cm-').TheEImassspectaof1showedam0lecularionpeakatm/z322,whichindicatedthemoleculartbrmulatobeC17H22O6,consistentwiththe13C-and1H-NMRspectIald…     

Artselenoide, a New Dimeric Guaianolide from Artemisia selengensis

Inaprelindnary.ommunication',wehavereportedonanewguaianolideartseleninisolatedfromArtemisiaselengensisTurcz(Compositae).Inthepresentpaperwedescribethestructureelucidationofartselenoide1obtainedasanewdimericguaianolidefromthesamepart.1wasobtainedascolorlesspowders,mpl85-l86D,[a]." l25(cO.l,MeOH).TheIRspectrumexhibitedabsorptionbandsduetohydroxyl(3435cm-'),Ylactone(l764cm-')anddoublebond(l648,l635,l456cm-')groups.Themolecularformu1aCstheooof1wasdeducedfromthedataofESIMS(Inlz5l9[M Na] ,53…     

Possible conformations of the seven-membered rings and relative stabilities of 1β,5α,6β,7α(H)- and 1α,5α,6β,7α(H)-guai-11(13)-en-6,12-olides

A calculation has been made by the method of molecular mechanics, using the MM2 program, of a number of stereomeres of 1,5,6,7(H)- and 1,5,6,7(H)-guai-11(13)-en-6,12-olides. The possibilities of the adoption by the seven-membered ring of particular conformations according to the type of its linkage with the 5-membered carbocycle have been considered. Questions of the influence of the orientation of the Me groups on the degree of distortion of the conformation of the seven-membered ring from the ideal and the relative stabilities of the various conformers are discussed.A. N. Nesmeyanov Institute of Organometallic Compounds, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 198–203, March–April, 1991.     

Study on the Total Synthesis of 3-Oxo-9β-Acetoxyilicic Acid─The Synthesis of 9β-Acetoxy-3(4),11(13)-Dien-5αH,7αH-12-Eudesmanoic Acid Methyl Ester

EudsmanetwCOInPOUnarewidlydistribUtedinthekingdomofplants.Becauseoftheirwide~ofbiologicalpropenies,~lyantif~cellgrowthinhiitoryandPlangrowthregUlatinactivihesl"'],eudesmandc~havbendIawinconsiderableattontion.IncounectionwithourlongtiIneffortinthesfi6ld.weareinteedintheSynthniOfanoveleudeSmanderivativ,3-oxo-99-aCetoWdcadd.,whichwasisofatalfrOmArtemiSiaPhaeolePisinl995tyTanetal'].ThCmoleculeisrathrmplexwithreSpeCttOstereochemsitry.Onthethen-carbonskeletonofthemolecule,therearefivcstCn…     

Possible conformations and relative stability of the 7-membered ring in 1α,5β,6,7α(H)-and 1β,5α,6,7α(H)-guai-11(13)-en-6,12-olides

Stereoisomers of 1,5,6,7(H)- and 1,5,6,7(H)-guai-11(13)-en-6,12-olides are calculated using molecular mechanics. The possibility of forming various conformations in the 7-membered ring is examined as a function of the fusion to the 5-membered C-ring. The effect of the methyl orientation on the conformation of the 7-membered ring and the relative stability of the conformers are discussed.Insitute of Phytochemistry, Karaganda, fax (3212)-43-37-73. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 54–56, January–February, 2000.     

Hydroacridines XXI [1]. 13C NMR Spectroscopic Investigation of the Stereoselectivities of Quaternizations of N-Alkyl Derivatives of (4aα,8aβ,9aβ,10aα)- and (4aα,8aα,9aβ,10aα)-Tetradecahydroacridine

Summary.  The stereoselectivities of the quaternization reactions of (4aα,8aβ,9aβ,10aα)- and (4aα,8aα,9aβ,10aα)-tetradecahydro-10-methylacridine with methyl- and ethyl iodide as well as those of (4aα,8aβ,9aβ,10aα)- and (4aα,8aα,9aβ,10aα)-10-ethyl-tetradecahydroacridine with methyl iodide were investigated using ¹³C NMR spectroscopy including ¹³C-labelling where appropriate. The methylations of both N-methyl amines occur by predominant (60% and 75%, respectively) equatorial approach, their ethylations occur sterospecifically by equatorial approach, and the methylations of the N-ethyl amines occur by highly stereoselective (> 90%) axial approach of the quaternizing reagent. Received October 27, 1999. Accepted November 22, 1999     

Studies on taxol biosynthesis. Preparation of 5α-acetoxytaxa-4(20),11-dien-2α,10β-diol derivatives by deoxygenation of a taxadiene tetra-acetate obtained from Japanese yew

The putative metabolite, 5α-acetoxytaxa-4(20),11-dien-2α,10β-diol (7), which is a promising candidate as a biosynthetic pathway triol in taxol biosynthesis, has been prepared by Barton deoxygenation of the C-14-hydroxyl group of a differentially protected derivative of natural 2α,5α,10β-triacetoxy-14β-(2-methyl)-butyryloxytaxa-4(20),11-diene (8), a major taxoid metabolite isolated from Japanese Yew heart wood. The synthetic protocol devised, is amenable for the preparation of isotopically labeled congeners that will be useful to probe further intermediate steps in the biosynthesis of taxol.     

Synthesis of 5α, 13α, 14α-Androstan-16-One and 5α, 13β, 14β—Androstan-16-One Using a Novel 17–16 Carbonyl Transposition

In the course of current work on the conformational analysis of cis-hydrindanones¹, we required 5α, 13α, 14α and 5α, 13β, 14β-androstan-16-one 5 and 10 the C and D rings of which provide rigid models of the two conformations of cis-hydrindan-2-one.     

Synthesis of driman-8α,11-diol from sclareol through 8α,12-epoxy-14,15-bisnorlabdan-13-one

A four-step synthesis of driman-8,11-diol from sclareol in 44% total yield is described that includes the intermediates (12R)-8,12-epoxy-14,15-bisnorlabdan-13-one, (12S)-8,12-epoxy-12-acetoxy-13,14,15,16-tetranorlabdane and 8,12-epoxy-13,14,15,16-tetranorlabd-11-ene.Institute of Chemistry, Academy of Sciences of the Republic of Moldova, Kishinev, fax (3732) 73 97 75, Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 124–125, March–April, 2000.     

Daphkoreanin, a New Coumarin Glucoside from Daphne Koreana

DaphneNakai(Thymelaeeaceae)isakjndofbushdisIn~overtheChinandedasaboedmedcinefortheboentofcoIDnaIyhaItforwtforcmpblwtedcieq,theuhasandedcta.SeVenforcouInarinsthelwidaP~daPtwdaPhnetin-to6opucosideumbeili~~daP~daPhnorinandaknownbobobebeenbobofortherootsndtriornedl1.the~onorchntriledtotheholallonofanewcoumaringlucoside~.WewoulliketOedbetheroelocboofthenewcompundinthe~COmIn~onThen-BANsolublepothonobtahadrithe95%EtoHboofthedriedroOtsndStemSofDkoarewassub~to'~lOW~ereCConsilicagel,elededC…     

Donhexocin,a New Non-tetrahydrofuran Acetogenin from Goniothalamus Donnaiensis

TheADnonaousaeetogeinnsareaasgroUPofPoweifulIyhioaodveagentS,allnedy2(X)acetogeninsbeboidsdrisevedpoofthendyAnn-.1ourinveshgahonontheethanolicexbooftherootSofGontothalamUSdeednsisresultedintheisolahondanovelAnnasaeetogenin,donhxodn(1),whichisaC-35nontetrahtherrIIF)aceto~bearingaixhyboylsincludintWovic-diolsystems.~ocin(1)wasisoatedasawhiteamtw~,MPoosoC'lap'.+8.O(MCh,co.lo),ffemolccularforaofCs,Ho'O,wasdsbyFABMSaxlelementaIanalysis(fbUnC,68.l3,H,lo.64%;C,.H.'os~C,68.4(),H,lO.75%…     

Eupatoranolide, a New Sesquiterpene Lactone from Eupatorium adenophorum

Inourinvestigationonthebioactivecomponentsfromplants,thepreliminarybioassaystudiesshowedthatthepetroleumetherextractofEupaloriumadenOPhorumpossessedpotentialinsectantifeedantandinsectcideactivities.Inthepreviouspaper'.weisolatedanewphenylglucosidefromtheaerialpartsofE.adenophorum.FurtherstudyonflowersofE.adenophorumledtotheisolationoftwelvecompounds.Theirstructureswereidentifiedbyspectralanalysisandchemicalreactionasanewsesquiterpenelactonenamedeupatoranolide,2-acetoxy-3,4,6,11-tetradehydroc…     

The Preparation of 1H-Pyrazole-1-carboxylic Acid, 1, 1-Dimethylethyl Esters from Dilithiated C(α), N-Hydrazones of Hydrazinecarboxylic Acid, 1, 1-Dimethylethyl Ester

C(α), N-Hydrazones of hydrazinecarboxylic acid, 1, 1-dimethylethyl ester [C(α), N-carbo-t-butoxyhydrazones] were metalated with excess lithium diisopropylamide, and the dianion-type intermediates were condensed with select aromatic esters followed by acid cyclization to substituted 1H-pyrazole-1-carboxylic acid, 1, 1-dimethylethyl esters (N-carbo-t-butoxypyrazoles).     

New Synthesis of α-Bromo-α,β-Unsaturated Esters

A synthesis of α-bromo-α,β-unsaturated esters 2 from tert-butyl α-(trimethylsilyl)-α-bromoacetate (1) and carbonyl compounds is described.     

A taxane with a novel 9α,13α-oxygen bridge from Taxus cuspidata needles

A novel taxane with an unprecedented hemiacetal ring between C-13 and C-9 was isolated from the needles of Taxus cuspidata. The structure was characterized as (12αH)-2α,10β-diacetoxy-5α-cinnamoyloxy-9α,13α-epoxytax-4(20)-ene-11β,13β-diol (1). This is the first example of a natural taxane with a C-13 and C-9 oxygen bridge to form an unusual 6/8/6/6-membered ring system.