淡色库蚊产卵引诱信息素的立体选择性合成

手性烯醇硅醚——薄荷烷氧基二甲硅烷基环戊用烯醇硅醚与十一醛进行立体选择性亲电取代反应，得到赤式占优势的２－（１－羟基十一烷基）环戊酮，分离纯化后经Ｂａｃｙｅｒ－Ｖｉｌｌｉｇｅｒ重排和乙酰化，得到淡色库蚊产卵引诱信息素——赤式６－乙酰氧基十六碳烷酸－５－内酯。其中活性组分（－）－（５Ｒ，６Ｓ）异构体占５０％，较一般非立体选择性合成法提高２５％。     

A Short and Stereoselective Synthesis of the （-）-（5R, 6S）-6-Acetoxy-hexadecane-5-olide

(-)-(5R, 6S)-6-Acetoxyhexadecan-5-olide 1, a natural mosquito attractant pheromone,was synthesized from readily available aldehyde 2 and cyclopentanone 3 using L-proline-catalyzed asymmetric aldol reaction as the key step.     

Stereoselective Synthesis of (6R)-6-(5-Methyl-2-furyl)-2-oxocyclohexanecarboxyl-10', 2'-Sultam

PseudolaricacidA(l)whichexhibitsantifungalandantifertilityactivitieswasisolatedfromPeudolarl-xKaenlpjbriGord'.Theabsoluteconfigurationsofthesechiralcenterswereassignedtobe3S,4S,10RandIIRrespectively'.Accordingtotheretrosyfltheticanalysis.theskeletonofIcouldbeconstructedbyintramolecular[4- 31cycloadditiontyomaseven-memberedlactone2(Schemel)whichcouldbeobtainedfrom(6S)-6-Thesynthesisbeganwithbetalprotected0-ketoacid4,tbllowedbyamidationwith(-)-camphorsultamandDCCtoobtainapairofdiastereomer…     

Synthesis of (5R,8S,10R)-6-(Allyloxy)- and (5R,8S,10R)-6-(Propyloxy)ergolines from the 6-Methyl Precursors

Novel (5R,8S,10R)-6-(allyloxy)- and (5R,8S,10R)-6-(propyloxy)ergolines have been synthesized by use of a Meisenheimer [2,3]-sigmatropic rearrangement of a (5R,8S,10R)-6-allyl-ergoline N⁶-oxide as key step.     

Synthesis of (5R)- and (5S)-5-Methyl-5, 6-dihydrouridine Derivatives

The hydrogenation of 2′, 3′-O-isopropylidene-5-methyluridine (1) in water over 5% Rh/Al₂O₃ gave (5 R)- and (5 S)-5-methyl-5, 6-dihydrouridine (2) , separated as 5′-O-(p-tolylsulfonyl)- (3) and 5′-O-benzoyl- (5) derivatives by preparative TLC. on silica gel and ether/hexane developments. The diastereoisomeric differentiation at the C(5) chiral centre depends upon the reaction media and the nature of the protecting group attached to the ribosyl moiety. The synthesis of iodo derivatives (5 R)- and (5 S)- 4 is also described. The diastereoisomers 4 were converted into (5 R)- and (5 S)-2′, 3′,-O-isopropylidene-5-methyl-2, 5′-anhydro-5, 6-dihydrouridine (7) .     

(一)-莰烷磺内酰胺法立体选择性合成米象虫和玉米象虫聚集合信息素

本文以(-)-莰垸-2,10-磺内酰胺(2)为原料经六步反应立体选择性地合成了米象虫和玉米象虫聚集信息素(4S,5R)-Sitophilure,两个手性中心是由N-丙酰基-莰烷-2,10-磺内酰胺(3)与丙醛进行的不对称顺式醛醇缩合反应一次性引入的。该全合成的对映异构体纯度可达96％e.e。     

Synthesis and Conformation of (5R,8R,10R)-8-(Methylthiomethyl)ergoline-6-carboxamidine

The title compound 7 and two related novel ergolines have been synthesised from (5R,8R,10R)-8-(methyl-thiomethyl)ergoline-6-carbonitrile ( 4 ). The guanidine function of 7 induces a boat conformation of ergoline-ring D, as demonstrated by a careful NMR spectroscopic analysis of 7 and its N-hydroxy congener 6 . Diphenylphosphinodithioic acid has been used to convert the cyanamide function of 4 into the thiourea function at (5R,8R,10R)-8-(methylthiomethyl)ergoline-6-thiocarboxamide ( 5 ).     

A Convenient Stereoselective Synthesis of (1R,2S,3R,4S)-3-(Neopentyloxy)isoborneol

A convenient preparation of (1R,2S,3R,4S)-3-(neopentyloxy)isoborneol (= (1R,2S,3R,4S)-3-(2,2-dimethyl-propoxy)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol; 1a ), a valuable chiral auxiliary, is described. The synthesis involves six steps starting from the readily available camphorquinone ( 5 ) and gives 1a in 48% overall yield. The key step is the chemoselective hydrolysis of the less hindered 1,3-dioxolane moiety in the camphorquinone di-acetal 4 .     

Synthesis of (3R,5S,6R) 2,6-Diacetoxymethylclavam from D-Galactal

Abstract

N- (t-Butyl)dimethylsilyl-2- C: 1 - N- car bony 1 - 2 -deoxy- α-D-galactopyran-osylamine (1) was tritylated and the product was subjected to a glycolic cleavage to give dialdehyde 10. Subsequently, compound 10 was transformed into bromide 14 using standard procedures. The fluoride anion induced cyclization in 14 afforded clavam 15.     

Electrochemical Synthesis of the Sex Attractant Pheromone of the Housefly: (Z)-9-Tricosene

The electrochemical synthesis of muscalure, (Z)-9-tricosene( 1 ), has been carried out by coelectrolysis of erucic acid ( 2 ) and propionic acid ( 3 ) in an undivided cell in methanol. To optimize the yield of the cross coupled product 1 , the reaction has been studied in detail by varing different parameters, viz., electrode material, current density, molar ratio of 2 to 3 , degree of partial neutralization and quantity of water in methanol.     

(1R,6R)-(+)-鱼腥藻毒素的合成

鱼腥藻毒素(Anatoxin-a)是自兰藻类水华鱼腥藻(Anabaena flos-aquae)中分离的一种氮杂双环胺类生物碱,其化学结构及绝对构型经X光晶体衍射法测定分析为:(1R,6R)(+)-2-乙酰基-9-氮双环[4.2.1]壬-2-烯,简称为AnTX-a。     

Synthesis and modeling study of (2S,5R,6R)- and (2S,5R,6S)-6-hydroxy- 8-(1-decynyl)-benzolactam-V8 as protein kinase C modulators

[structures: see text] Both (2S,5R,6R)- and (2S,5R,6S)-6-hydroxy-8-(1-decynyl)benzolactam-V8 were designed and synthesized as PKC modulators. Biological assays reveal the (6R)-ligand to be 20-fold more potent than its (6S)-counterpart in binding to PKC alpha.     

(5S,6R)-2-(4-甲基)苯基-6-[(1R)-叔丁基二甲基硅氧乙基]-青霉烯-3-羧酸乙酯的合成研究

青霉烯[1]类抗生素是近年来发展很快的一种非典型β-内酰胺抗生素.青霉烯类化合物[2]具有广泛的抗菌活性,具有优于碳青霉烯类抗生素的特点,其固体化合物和酯型前药可口服吸收,不易被β-内酰胺酶水解,同时对脱氢肽水解酶-I( DHP-I )较碳青霉烯稳定.     

Asymmetric Synthesis of (-)-(2R,3R,6S)-Irnigaine

Introduction　　Asarelativelynewmemberofnaturalalkaloidswith2 ,6 disubstituted 3 piperidinolskeleton ,irnigaine 1wasisolatedfromthetubersofArisarumVulgare (Araceae)in1995byMelhaouiandBode .1Itsstructureandrelativeconfigurationswereelucidatedby1HNMRstudiesandtheabsoluteconfigurationwasproposedonthebasisofitsopti calrotation .1Soonafterthen ,Meyerandhisco workersreportedthefirstsynthesisof (- ) (2R ,3R ,6S) irni gaineandtheconfigurationconfirmation .Althoughtheirsynthesisroutewasshortan…     

Synthesis of (−)-(5R,6S)-6-acetoxyhexadecan-5-olide by l-proline-catalyzed asymmetric aldol reactions

The natural mosquito attractant pheromone, (−)-(5R,6S)-6-acetoxyhexadecan-5-olide 1, was synthesized from readily available aldehyde 3 and cyclopentanone 4 using l-proline catalyzed asymmetric aldol reactions as the key step.     

利用工业废弃物中获得的(R)-5-甲基-δ-戊酸内酯为原料合成(2R,6R)-2,6,10-三甲基十一醇

(2R,6R)-2,6,10-三甲基十一醇(1)是维生素E、维生素K和植醇的基本结构单元. 利用从甾体皂甙元氧化降解产生的工业废弃物中所获得的手性化合物(R)-5-甲基-δ-戊酸内酯(6), 先将其转化成为化学性质稳定的(4R)-甲基-5-甲氧甲氧基戊酸甲酯(7), 再经十二步反应, 以14.1%的总收率合成得到了目标化合物(2R,6R)-2,6,10-三甲基十一醇(1).     

(+)-(1S,2S,5R)-8-联苯薄荷醇的合成

以(R)-( )-pu legone为起始原料,经1,4-加成,还原两步反应合成了手性辅助试剂( )-(1S,2S,5R)-8-联苯薄荷醇及其差向异构体(-)-(1R,2S,5R)-8-联苯薄荷醇,总产率95%。其结构经1H NMR,13C NMR,IR,MS和X-射线衍射仪表征。     

A Facile and Highly Stereoselective Reductive Debromination of Anhydro-6- (R)-Hydroxyethyl- 6-Bromopenicillin

Reductive debromination of anhydro-6-(R)-hydroxyethyl-6-bromopenicillin 7 by zinc in ammonium acetate gave 9 in 81% yield with high stereoselectivity of 6-(α):6-(β)=13:1.