立体选择性合成2-呋喃甲酰基-3-芳基-4-乙氧羰基-5-甲基-反式-2,3-二氢呋喃

溴化呋喃甲酰基甲基三苯鉮1与2-乙酰基-3-芳基丙烯酸乙酯2以碳酸钾为碱，在四氢呋喃中室温反应，可以较好的收率、高立体选择性地生成反-2-呋喃甲酰基-3-芳基-4-乙氧羰基-5-甲基-2,3-二氢呋喃3。产物结构均经波谱予以确定。本文还提出了生成产物的可能机理。     

2,3,4,5-四取代-顺-2,3-二氢呋喃立体选择性合成方法的研究

研究了3种合成2甲氧羰基3芳基4乙酰基5甲基顺2,3二氢呋喃(7)的方法.方法1:用甲氧羰基亚甲基三苯基胂(5)与3(取代苯甲叉)2,4戊二酮(6)反应;方法2:用溴化甲氧羰基甲基三苯基胂(4)在碳酸钾存在下与戊二酮6反应;方法3(分步一锅法):三苯基胂(2)与溴代乙酸甲酯(3)加热反应,生成的产物不经分离,冷却至室温,加入碳酸钾和6继续反应.     

桃柱螟性信息素的立体选择性合成

分别以10-十一碳烯酸和丙炔醇为起始原料,通过炔化物路线(第1个中间体是10-十一碳炔醇-1(5),第2个中间体是10-十六碳炔醇-1(8))分别立体选择性合成了桃柱螟性信息素成分(E)-10-十六碳烯醛(1)和(Z)-10-十六碳烯醛(2)。     

苄基酒石酸甲乙酯的立体选择性合成

本文报道了赤式苄基酒石酸甲乙酯(3)的立体选择性合成,其~1H核磁共振谱、红外光谱和质谱与预期的结构一致。这个方法对合成其它具有赤式酒石酸结构的天然产物有一定的参考价值。     

微波促进Wittig-Michael串级反应立体专一性合成ω-氨基-β-D-呋喃核糖酸衍生物

以D-核糖为原料,在微波促进下,利用2,3-O-异丙叉基-D-核糖2与叶立德3(Ph3P CHCOOEt)的Wittig反应和Michael加成,立体专一性地合成了β-D-呋喃核糖酸酯类化合物,再经叠氮化及还原反应,得到ω-氨基-β-D-呋喃核糖酸衍生物.在微波辐射下,该Wittig-Michael串级反应的效率得到显著提高,反应时间由12 h缩短为10 min,收率达到91%.反应具有非常好的β-立体选择性,在碱性条件下处理后,α-异构体可转变成热力学稳定的β-异构体,从而得到单一的β-异构体.计算结果表明,β-异构体4b比α-异构体4a具有更高的热力学稳定性.     

立体选择性合成2-(a-噻吩甲酰基)-3-取代苯基-4-乙氧羰基-5-甲基-反式-2,3-二氢呋喃

溴化(a-噻吩甲酰基)甲基三苯鉮1与3-取代苯甲叉基-2,4-戊二酮 2以碳酸钾为碱,在苯中55℃条件下反应,可以较好的收率、高立体选择性地生成反-2-(a-噻吩甲酰基)-3-取代苯基-4-乙氧羰基-5-甲基-2,3-二氢呋喃3。产物结构均经波谱予以确定。本文还提出了生成产物的可能机理。     

各种烯基锆化合物的合成及其在立体选择性合成二(三)取代的烯烃中的应用

烯基锆化合物及硒基烯基锆化合物、锡基烯基锆化合物、磺酰基烯基锆化合物、亚磺酰基烯基锆化合物、硅基烯基锆化合物等金属或杂原子取代的烯基锆化合物 ,可通过锆氢化反应高产率和高选择性地制得 .这些试剂可与各种亲电试剂反应立体选择性地合成二取代或三取代的烯烃化合物     

Simple Approach to the Highly Stereoselective Synthesis of trans-1,2-Cyclopropane Derivatives

In the presence of KF·2H2O, furoylmethyltriphenylarsonium bromide （1a） or thienoylmethyltriphenylarsonium bromide （1b） reacted with 2-[（un）substituted benzylidene]malononitrile （2） in chloroform at room temperature to give trans-3,3-dicyano-1-furoyl-2-[（un）substituted phenyl]cyclopropane （3a） or trans-3,3-dicyano-1-thienoyl-2- [（un）substituted phenyl]cyclopropane （3b） respectively in good yield with high stereoselectivity. The structures of product 3 were confirmed by IR, MS, 1^H NMR, 1^H-1^H COSY and microanalysis. The relative configuration of product 3 was determined by 1^H-1^H NOESY technique. The mechanism for the formation of product 3 was also proposed.     

Stereoselective Synthesis of 1-Aminocyclopropanecarboxylic Acid Derivatives via Ylide Cyclopropanation of Dehydroamino Acid Derivatives

1‐Aminocyclopropanecarboxylic acid derivatives are synthesized from readily available dehydroamino acid derivatives via sulfur ylide. A range of different ylides are employed and the corresponding aminocyclopropanes are afforded with reasonable diastereoselection in good yields.     

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…     

贫电子环丙烷衍生物的化学

综述了贫电子环丙烷衍生物——顺式-1,2-二取代-6,6-二烷基-5,7-二氧螺- [2,5]-4,8辛二酮与含氧、氮、硫等亲核试剂反应的研究进展。     

Novel and Efficient Synthesis of Pyrimidine Derivatives

A new series of 1-alkyl-2-oxo-1,2-dihydro-pyrimidine-5-carboxalic acid amides is described. The reaction of N-((E)-3-(dimethylamino)-2-formylacryloyl) formamidine, an intermediate obtained by Vilsmeier–Haack formylation of acetonitrile with various mono-substituted ureas, provides such compounds in good yields.     

The Stereoselective Synthesis of Indoloquinolizines

Carboline was reduced with lithium aluminum hydride to provide carboline-alcohol whichreacted with methyl vinyl ketone to form the corresponding hydroxymethyl-amino-ketone. Underphase transfer condition it can be converted into enantiomerically pure indoloquinolizines. The cycliza-tion mechanism was also illustrated here.     

Stereoselective Synthesis of (±) Neocnidilide

The lactone neocnidilide 8 occur in the roots of Cnidilide officinale1 which is shown to inhibit the growth and toxin production of mycotoxin-producing fungi2. Although The synthesis of lactones 7, which is stereoisomer of cnidilide, and 8 had been reported by others3, 4, we would like to report the highly stereoselective synthesis of its racemic isomer 8 as shown in Scheme 1. Scheme 1 COOHHOOCbcOOHH1234d5eOHOHHH 6fOOHHH 7g8COOHOHa12345673a7aOHHOH1235673 a7a1234561'1'2'…     

New Stereoselective Synthesis of 4-Butyl-α-agarofuran

A potent anxiolytic 4-butyl-α-agarofuran (AF-5) was synthesized from ( )dihydrocarvone. Acid catalyzed hydration of ( )dihydrocarvone and interconversion with β-O-ketone 8 and the key intermediate α,β-unsaturated ketone 5 made this synthesis more practical.     

立体选择性合成内型N-Boc-N-去甲托品醇

以托品酮为起始原料,与氯甲酸氯乙酯经脱甲基化反应制得脱甲基托品酮（1）; 1与Boc酸酐反应制得N-Boc-N-去甲托品酮（2）;以三仲丁基硼氢化锂为还原剂,2经还原反应立体选择性合成了内型N-Boc-N-去甲托品醇（内型/外型=6.5/1）,总收率60%,其结构经¹H NMR和ESI-MS确证。