Total Synthesis of dl-Ligustiphenol

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Total Synthesis of Saprorthoquinone

Alarge1lumberoforthoquinonenaturalproductSwereisolatedfromsalviaspecies.BioassayonU1esecompoundssl1otvedthattileyhadalotofbio1ogicalachvihessucl1asanhbacterial,corolleq'arterydilator,anhtumoretc.TlhshadledtomanSynthesesofthem.Saprorthoqninolle(l),anaturalorthOquinone,t`asisolatedfromtherootSofsaIviaPrionitisHalleel'Jl`41ichtmsusedinfolkmedicinefortrtutmentofInandiseases.Theiulhalbioassayshowedthatsaprortlloqull1onehadachvityinleukemiaPaseteSt.Recenhy,MatSumotoetal.reportedaSynthesisofsa…     

Total Synthesis of Przewaquinone A

PrzetvaquinolleA,anaturalortloquinoneisoIatedfromSalviaPrzewakiiMtalmvarmandarinorunIShb.['J.hasbeenshowedanhtumorachvityinaVariety'oftumormodels,sucha5Let`dsIungcarcil1oma,Il1e1anolnaBl6,sarcomal8Oandleuke1niaPss8,bothinvitroandvivo.Inthepresentpaper,h1efirsttota19'11tl1esisofprzett2q[linoneAisdescribed.Targetmoleculeunpreparedtliroughareactionsequence(asshoxvnil1scheme.).Con1pound5ttasobtalnedbycyclizahonof4in56.l%}jeld.Dicarbox})licacid5washeatedwithcoPperPOwderinquinolinetoaffordmo…     

Total Synthesis of (+)Villosol

Villosol,aniridoid,wasisolatedin1985fromChineseherbmedicineP8triniaviIios8'itSstrUctUrewasproPOsedas(A)ll].lnourpreviouspaperi2],wehavereP0rtedthesynthesisofthesubstance(l)A,andf0undittobesPectraIlynonidenticalwiththenaturalisolate.Later,throughX-rayanalysisl'],wehaveconfirmedthatthesmictUreofvillosolwasB.Herein,wedisclosethefirstStereoselectivetotalsynthesisof(+)B.Oursynthesisbeganwithcompound2,whichwasreadilypreparedandresolvedtoitSoPticalformsinlargescalebyAnownmethodI41.After(l)2w…     

Total Synthesis of Homodimericin A

We report the concise total synthesis of homodimericin A ( 1 ), a recently identified fungal metabolite bearing an unprecedented molecular architecture. The success of the approach hinges on a series of rationally designed and bioinspired transformations, including a Moore rearrangement to assemble the monomeric hydroquinone precursor, homodimerization through double Michael addition to construct the planar A/B/C tricyclic framework, and a tandem Diels–Alder reaction/carbonyl–ene cyclization to forge the congested D/E/F tricyclic cage motif. Unequivocal evidence for the elucidated structure of homodimericin A was also provided by this study.     

Total Synthesis of α-Elvucitabine

Total synthesis of α-elvucitabine was achieved in 26% overall yield by a concise nine-step procedure starting from L-lyxose, with trimethylsilyl trifluoromethaneoulfonate (TMSOTf)–mediated stereocontrolled α-N-glycosidation and olefination through Barton–McCombie deoxygenation being the key steps, and the stereochemistry of the product was determined by nuclear Overhauser effect spectroscopy.     

Total Synthesis of Lajollamycin B

The first total synthesis of lajollamycin B, a structurally novel nitro-tetraene spiro-β-lactone/γ-lactone antibiotic, is described. The convergent synthesis involves the construction of the C8′–C11′ nitrodienylstannane and its coupling with the segment prepared from the C1′–C7′ ω-iodoheptadienoic acid and the right-hand heterocyclic fragment, which has been utilized for our previous syntheses of oxazolomycin A. The revision of the geometry of the terminal Δ^{10′, 11′}-double bond from E to Z is also described for the structure of natural lajollamycin B.     

Total Synthesis of N-Methylsansalvamide A

Sansalvamide A is a cyclic depsipeptide, isolated from a marine fungus of the genus Fusarium by Belofsky in 19991. The depsipeptide displays cytotoxic and antiviral activities, and also possesses inhibitor of MCV topoisomerase2. The corresponding amide de…     

Total Synthesis of (−)-Albocycline

The macrolactone natural product (−)-albocycline is a promising antibiotic candidate for the treatment of both methicillin resistant Staphylococcus aureus (MRSA) and vancomycin-resistant strains. Herein we report a concise total synthesis of (−)-albocycline in 14 steps from commercially available methyl (R)-3-hydroxybutyrate. Novel key steps include the highly regio- and stereoselective reactions of chiral N-sulfinyl metallodienamines (NSMDs) with aldehydes and the Davis oxaziridine, in addition to the Horner–Wadsworth–Emmons olefination of N-sulfinyl imines.     

Stereoselective Total Synthesis of Chrysanthemol

Recently,muchattentionhasbeenpaidtothesynthesisofbioactivenaturalproducts.Chrysanthemol,aneudesmanetypesesquiterpene,firstisolatedfromChrysanthemumindicumL.byD.Q.Yuetal.',showedstrongantiinflanunatoryactivityinmice.ThestructureandabsolutestereochemistryofchrVsanthemolwereelucidatedas1ThesyntheticrouteofchrysanthemolflomR-( )-carvoneisdepictedinScheme1:n.50%aqACOH,2hr;d)KOH,EtOH,oOC,3hr,e)Na,propanol,50"C,6hr,67.2%;66.7%i)m-CPBA/NaHCO3,CHZC12,r.t.,3.5hr,84%;TreatmentofR-( )-carvon…     

Total Synthesis of the Analogue of Icogenin

It was well known that furostan saponin was a kind of natural products with a broadrange of promising pharmaceutical properities1. Structurally, furostan saponins usuallyhave bidesmosidic sugar moieties substituted at 3-OH and 26-OH position2. However,fur…     

Improved Synthesis of Icaritin and Total Synthesis of β-Anhydroicaritin

Natural products icaritin and β-anhydroicaritin with P-glycoprotein(P-gp) inhibitory activities were ciently synthesized in nine steps from commercially available phloroglucinol. A modified Algar-Flynn-Oyamada cyclization and relay Claisen-Cope rearrangement were employed in this concise route. Oiir synthesis offers opportunities to synthesize various icariin analogues for biological and pharmacological investigations.     

Bioinspired Total Synthesis of Homodimericin A

Homodimericin A is a remarkable fungal metabolite. This highly oxygenated racemic unsaturated polyketide poses a significant synthetic challenge owing to its sterically demanding central cagelike core containing eight contiguous stereogenic centers (including three quaternary stereocenters) and several carbonyl functionalities. On the basis of its proposed biogenetic synthesis, we designed a total synthesis of homodimericin A that proceeds in seven steps and features a double Michael reaction, an intramolecular Diels–Alder reaction, and an ene reaction.     

Asymmetric Total Synthesis of Cephanolide A

The first asymmetric total synthesis of cephanolide A, a complex hexacyclic C₁₈ dinorditerpenoid from cephalotaxus sinensis, was achieved. The synthesis features a convergent strategy, which provides a flexible approach to prepare the biogenetically cephalotaxus diterpenoids and structurally related derivatives for biological studies. A mild intramolecular Prins cyclization was developed to construct the central hexahydrofluorenol skeleton (A-B-C ring), which relies on the originally proposed hydroacylation strategy. A remote hydroxy group directed hydrogenation was applied to stereospecifically reduce the tetra-substituted enone unit. A sequence of ring forming steps, including lactonization, cation mediated etherification and Friedel–Crafts cyclization, was efficiently utilized to forge the cage-like skeleton.     

Asymmetric Total Synthesis of Hispidanin A

Asymmetric total synthesis of the dimeric diterpenoid hispidanin A was accomplished by non-catalytic Diels–Alder cycloaddition at room temperature. The synthesis relies on iron-catalyzed coupling to construct a Z-configured trisubstituted alkene, an iron-catalyzed radical cascade to generate a labdane-type diene, and both Yamamoto cationic polyene cyclization and palladium-catalyzed Stille coupling to generate a totarane-type dienophile.     

Total Synthesis of (−)-Glaucocalyxin A

A practically useful method for the formation of the highly oxygenated bicyclo[3.2.1]octane ring system through Mn(OAc)₃-mediated radical cyclization of alkynyl ketones was developed, which opens up a new avenue for the total synthesis of a number of highly oxidized diterpenoids. Application of this method enabled the first total synthesis of (−)-glaucocalyxin A. Other salient features of the synthesis include a highly enantioselective conjugate addition/acylation cascade reaction, a Yamamoto aldol reaction, and an intramolecular Diels–Alder reaction to assemble the A/B ring system.     

Total Synthesis of Bilobetin and Isoginkgetin

BilobetinandisoginkgetinisolatedfromtheleavesofGinkgobilobaarebiflavoneswithadissymetricall-3',lI-8corinection,ll]SinceextratSfromtheleavesofGihkgobiIoba(maidenhairtree)werewidelyinvestigatedfortheraPeuticaluses,l2landthesynthesisofthesetWobifiavoneshasnotbeenreported,wewishtodescribethetOtalsyntheticprocedureinthispaper.WeStartedwiththeknownphloroacetophenonewhichcouldbeeasilyobtainedbyHoeschreactionbetWeenphloroglucinolandacetonitrile.AfterselectiveprotectingitstWohydroxygroupswithisopr…     

First Total Synthesis of 6-Oxodendrolasinolide

~~First Total Synthesis of 6-Oxodendrolasinolide1.For a report on vinyl dithiane regioselectivity and similar reactions, see: (a) W. S. Murphy, S. Wattanasin, J. Chem. Soc, Perkin Trans. 1, 1980, 2678. (b) L. Colombo, C. Gennari, M. Santandrea, et al, J. …     

First Total Synthesis of 7-O-Geranyl-pseudobaptigenin

Isoflavones are a class of compounds mainly occurring in species of the Leguminosae family. These compounds have received much attention recently due to their interesting biological activities1. They have been found to act as the beneficial role in the prevention of hormone based cancers and coronary heart diseases, as well as being potent antioxidant compounds2. 7-O-Geranyl-pseudobaptigenin 1 was first isolated from the root bark of Millettia griffoniana3. The synthesis of 1 has not been re…     

First Total Synthesis of Cleroindicin B,(±) Cleroindicin C and E

The isolation of cleroindicins B, C and cleroindicin E, together with three novel related compounds cleroindicins A, D and F, from chinese folk medicine Clerodendrum indicum Linn. was reported before1. Pharmaceutical studies showed that cleroindicin C has certain anticancer activity, so its total synthesis attracted our considerable interest.Cleroindicin B Cleroindicin C Cleroindicin EThe commercially available 2-(p-methoxyphenyl) ethanol 1 was selected as the starting material. Compound…