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.     

Synthesis of α-Telluroketones

α-Telluroketones were prepared by reacting 4-methoxyphenyltellurium trichloride either with ketones or silyl enol ethers of ketones. The products upon pirolysis furnish α-chloro ketones.     

Synthesis of Multidentate Squaraines

To search for more better sensitizer of organic solar cell,a series of multidentate squaraines (Sq1-6) were synthesized, the structures were determined by elemental analysis,IR, UV-vis,^1H NMR and MS spectroscopies. The squaraing have good solubility in polar solvents such as EtOH,CH3COCH3,CHCl3, etc. as well as strong absorption band over 600-700 nm spectral range.     

Synthesis of α-alkylthioacroleins

Monomeric -alkylthioacroleins were obtained by the reaction of alkylthioacetaldehydes with formaldehyde and diethylamine hydrochloride. The structures of the -alkylthioacroleins were confirmed by NMR spectroscopy and mass spectrometry as well as by chemical transformations of these compounds.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 188–190, January, 1996.     

Synthesis of Modified Methylaluminoxane

Methylaluminoxane (MAO) is one of the most important cocatalysts of metallocene catalysts. The yield and activity of MAO is low when using Al2(SO4)3 nH2O and other inorganic hydrates to synthesize methylaluminoxane. The repeatability of this reaction is not good. The product cost is very high because one of the raw materials (Trimethylaluminium, TMA) to prepare MAO is very expensive. In addition, on standing, MAO toluene solution tends to gel. Gelled MAO can not be used to prepare su…     

Total Synthesis of dl-Ligustiphenol

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Direct Dimethyl Ether Synthesis

Dimethyl ether (DME) is a clean and economical alternative fuel which can be produced from natural gas through synthesis gas. The properties of DME are very similar to those of LP gas. DME can be used for various fields as a fuel such as power generation, transportation, home heating and cooking,etc. It contains no sulfur or nitrogen. It is not corrosive to any metal and not harmful to human body. An innovative process of direct synthesis of DME from synthesis gas has been developed. Newly developed catalyst in a slurry phase reactor gave a high conversion and high selectivity of DME production, One and half year pilot scale plant (5 tons per day) testing, which was supported by METI, had successfully finished with about 400 tons DME production.     

Efficient Synthesis of Octalone

A highly efficient and convergent approach for the synthesis of octalone 1, the focal intermediate for the synthesis of several sesquiterpenoids, was developed based on the cationic cyclization strategy of the functionalized oxabicyclic template 5.     

Total Synthesis of Saprorthoquinone

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

Synthesis of Pyrrole-Imidazole Polyamide

Small molecules that target specific predetermined DNA sequences have the potential tocontrol gene expression'. Realization of the high affinity binding and specific recognitionof DNA sequences by organic molecules is one of the focuses of biological chemistry.The natural products netropsin and distamycin are N-methylpyrrole containing di- andtripeptides, with binding specificity at sites of successive A.T or T.A base pairs of DNAin the minor groove'. Recently, N-methylimidazole is intro…     

The Synthesis of Polyfluoroalkylbiphenyl

Polyfluoroalkylated biphenyl was obtained from reaction of benzene with R_FI/Na_2S_2O_4 using cetyltrimethylammonium bromide (CTAB) as PTC followed by dehydrogenation with DDQ in 38-43% yield.     

Synthesis of α-oxazolinylalkanamides

The synthesis of α-oxazolinylalkanamides 2, based on the reaction of α-chloroalkyloxazolines 1 with hexacarbonyltungsten [W(CO)₆] and lithium amides, has been developed. A plausible mechanism involving the ketene 5 as the intermediate is also proposed.     

Synthesis of Short-Lived Radiotracers

Positron emission tomography (PET) has become a powerful tool for non-invasive investi-gations of basic biological and physiological processes in vivo, for example: blood flow, transport andmetabolism of natural substrates and localization and characterization of receptor systems. The aim ofthe synthesis of short-lived radiotracers is to develop the PET probes. Cyclotron-produced ~(11)C(t_(1/2):20min), 13N(t_(1/2):10min), ~(15)O(t_(1/2):2min) and ~(18)F(t_(1/2):110min) are gaining ever inereasing attentionand being actively utilized in clinical research and application, because they could be incorporated intonaturally oocurring biomolecules or drugs of various class without alteration of the compounds' definedfunctions in living systems. During recent years lots of ~(11)C and ~(18)F-labelled ligands has been synthe-sized for a number of receptor systems such as opiate, dopamine, serotonin, benzodiazepine, his-tamine, nicotine and muscarine. Ohmetentanyl, a new, highly potent and selective agonist for opiateμ-receptor found in this laboratory was labelled with carbon-11 in CEA, France.     

The Synthesis of Glycoglycerolipids

A convenient synthetic route was developed for the synthesis of the novel glycolipids: 1,2-di-O-acyl-3-O-(2‘-acylamide-2‘-denxy-ct-D-glucopyranosyl)-sn-glycerols. 10 new compounds of glycolipids with different acyl groups were obtained.     

Synthesis of γ-mercuridinitrohydrocarbons

Summary The denitration of -mercurinitro compounds has been studied and the corresponding organomercury dinitro derivatives have been obtained.     

Synthesis of α-hydroxyacetophenones

A general method for the preparation of α-hydroxyacetophenones is presented. Functionalized arylmagnesium species are transmetalated to the corresponding arylzinc intermediates, which undergo Cu(I)-catalyzed reaction with acetoxyacetyl chloride. Acidic hydrolysis of the acetate group releases the target α-hydroxyacetophenones with minimal production of undesired polymeric degradates that are often observed under alternative conditions.     

Synthesis of Oxa-Steroidal-Estrogen Analogues

Antiestrogencompoundraloxifene(LY13948lHCI)'andphytoestrogencompoundipriflavone'arenewgenerationdrugsforthetreatmefltofosteoporosis.RaloxifeneisnowinphaseillclinicaltrialandipriflavonehasalreadybeendevelopedintoadrugforthemarketinJapanandinitaly.ThoughthechemicalstfUcturesofthesetWocompoundsaresimilartothatofestrogentoacertainextent,andthemechanismsoftheirboneprotectingeffectsareillternallyconnectedwiththatofestrogen,thefemalehormonicactionsandtheriskforuterineandbreastcancerofthesetwocompo…     

Asymmetric Synthesis of Anisodine

Anisodine was synthesized from 3α-hydroxy-6β-acetyltropine in 11 steps. Laevorotary isomer of anisodine was prepared from the asymmetric dihydroxylation of compound 10 via the osmium catalyzed process employing p-chlorobenzoyl dihydroquinidine as the chiral ligands.     

Synthesis of CMC-Multipeptide Conjugate

AlthoughbioactivePeptidesplayessentialpl~nacologicalroles,manyofUlemarelimitedintheiruseastrigsduetotheirrapidclearancefromtilebodyandlowstabilitytoprotCase.Besidesthemodificationoftilepeptidebackbone,suchaspseudopeptides,Peptides,andPeptide-nucleicacidetNA),covalentbondingpeptidewigalsomemolecules,suchasbranched-chainPOlrpeptidepeCP)andpolyethyleneglycol(PEG)',isanotheraPProachtoelthancePephdebioavailability.ThemeritofaPephde-POlymerconjugateiswithoutmutationinPeptidebackbonewhilegain…     

Novel Synthesis of Barbiturates

Knovenagel reaction of barbituric acid with different aldehydes were used to synthesize new barbiturates. This is a novel method which can be used to synthsis various types of new generation of barbiturates which are different from the previously reported.