制备2-O-[1(R)-(9-次夹氧蒽基)-2-羟基乙基]丙三醇的新方法

以肌苷为底物,用两种性质相反的聚合物支载的高碘酸根离子和硼氢要离子一锅法合成了２－Ｏ－「１（Ｒ）－（９－次夹氧蒽基）－２－羟基乙基」丙三醇。该法具有操作简便,反应条件温和,缩短合成中线,无须分离中间体、产率较高等特点。     

自由基促进硫甲基取代的炔酮的环化反应

硫代吡喃酮是一种重要的结构骨架, 广泛存在于天然产物、潜在药物及生物活性分子中. 因此, 发展简洁、高效构建硫代吡喃酮的合成方法具有重要意义. 发展了一种自由基促进的硫甲基取代炔酮的加成环化反应来构建硫代吡喃酮环的新方法. 该方法具有底物适用性广, 一系列自由基前体如二苯基膦氧、硫酚、醛等都可以在该反应体系中实现转化. 机理研究表明, 自由基前体对炔酮的选择性加成得到C(sp ²)自由基中间体, 该中间体促进的C(sp ²)—S键构建及C(sp ³)—S键断裂是关键步骤.     

Synthesis and Crystal Structure of N—（1‘’‘’—Phenyl—2‘’‘’—hydroxyethyl）—2,3—naphthylenedicarboximide

IntroductionThe design and the synthesis of new chiral ox-azoline[1,2 ] and C2 symmetric bis( oxazoline) ligandsand the application of their metal complexes inasymmetric catalytic reactions have inspired manyscientists to great exertions in recent years[3— 8] .Our interest has been focussed on the studies ofenantioselective transition metal catalysis ofhetero-cyclic ligands[9— 11] . In the synthesis of our new de-signed ligands,what is crucial is to select a rigidcyclic backbone. Bis( oxazo…     

（E,E）—3,7—二甲基—2,6—癸二烯—1,10—二醇的高立体选择？…

1969年 Meinwald等 [1] 从一系列雄性蝴蝶的“hair pencils”中分离得到一组信息素成分 ,包括一类新颖的开链倍半萜骨架化合物 1— 3.尽管这些化合物在结构上与香叶醇相似 ,但利用香叶醇为原料进行合成的报道 [2～ 5] 还不多见 .本文以香叶醇为原料 ,报道了化合物 3的一条简便、高立体选择性的合成路线 .其关键反应步骤是 2 ,3-环氧醇的碘代重排反应和烯丙基烯基醚的克莱森重排反应 .a.Ac2 O,Pyridine,r.t.,2 h,yield 98% ;b.Se O2 ,t-Bu OOH,CH2 Cl2 ,r.t.,3 h,yield 73 % ;c.VO( acac) 2 ,t-Bu OOH,reflux,2 h,yield 90 % ;d.Ph3…     

(E)-2-(2-(1-(4-氯苯基)-3,5-二甲基-吡唑-4-基)乙烯基)-8-羟基喹啉的合成及光学性质

利用缩合反应合成了(E)-2-(2-(1-(4-氯苯基)-3,5-二甲基-吡唑-4-基)乙烯基)-8-羟基喹啉,利用质谱仪、核磁共振谱仪及红外光谱仪表征了其结构;并测定了其紫外光谱和荧光光谱.结果表明,所合成的8-羟基喹啉化合物在253.5 nm、303 nm和338.5 nm处出现紫外吸收峰;当激发光波长为225 n...     

Direct Synthesis of Benzofuro[2,3‐b]pyrroles through a Radical Addition/[3,3]‐Sigmatropic Rearrangement/Cyclization/Lactamization Cascade

A straightforward synthetic method for the construction of benzofuro[2,3‐b]pyrrol‐2‐ones by a novel domino reaction through a radical addition/[3,3]‐sigmatropic rearrangement/cyclization/lactamization cascade has been developed. The domino reaction of O‐phenyl‐conjugated oxime ether with an alkyl radical allows the construction of two heterocycles with three stereogenic centers as a result of the formation of two C?C bonds, a C?O bond, and a C?N bond in a single operation, leading to pyrrolidine‐fused dihydrobenzofurans, which are not easily accessible by existing synthetic methods. Furthermore, asymmetric synthesis of benzofuro[2,3‐b]pyrrol‐2‐one derivatives through a diastereoselective radical addition reaction to a chiral oxime ether was also developed.     

Efficient Synthesis of 2-(8-Quinolinoxy)-4H-imidazolin-4-ones

IntroductionMany N- heterocycles including 4H - imidazolin-4- ones show bactericidal and fungicidal activities,especially those with a 2 - alkoxyl substituent[1— 5] .The efforts to discover the new biologically activederivatives reflected by the still important numberof publications and patents have been devoted tothe subject[6— 11] .For example,some 2 - amino or 2 -alkylthio substituted 4H- imidazolin- 4- ones showsignificant antifungal and antibacterial activi-ties[7— 9] ,whereas others …     

Synthesis of Stable Atropisomers of Dialkyl-4-Ethoxy-1-(8-((2-ethoxy-2-oxoacetyl)-amino)-1-naphthyl)-5-oxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylates

Summary.  Protonation of the reactive 1:1-intermediate produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates with diethyl N,N′-(naphthalene-1,8-diyl)-dioxamate leads to a vinylphosphonium salt which undergoes an intramolecular Wittig reaction to produce dialkyl-4-ethoxy-1-(8-((2-ethoxy-2-oxoacetyl)-amino)-1-naphthyl)-5-oxo-4,5-dihydro-1H-pyrrole-2,3-dicarboxylates in good yields. The title compounds exist as stable rotamers as a result of restricted rotation around the single bond linking the naphthalene moiety and the heterocyclic system. The calculated free energy of activation for interconversion of the atropisomers amounts to about 102±2 kJ · mol⁻¹. Corresponding author. E-mail: isayavar@yahoo.com Received February 5, 2002. Accepted March 19, 2002     

Synthesis and Spectrophotometric Studies of 2-(2-Imidazolylazo)-5- Dicthylamino Phenol

Inasearchfornewsensitiveandselectiveorganicreagents,athoroughstudyofslomeofthequinolylazo,pridylazocompoundshasbeenreported.'-'Buttriazolylazoandimidazolylazocompoundshavenotbeenstudied.Inanearliespaper,'wehavereportedthesynthesisandspectrophotometricstudiesof2-(l,3,4-triazolylazo)-5-diethy\phenoland2-(5-carboxy-l,3,4-triazolylazo)phenol.Inthispaper,2-(2imidazolylazo)-5-diethylaminophenol(IZAPN)wasprepared,theconditionsofitsreactionwithcobaltwerestudied.Itwasfoundthatthereagenthadhighsensiti…     

Asymmetric radical cyclization of (2S,3S)-2,3-butanediyl, (2S,4S)-2,4-pentanediyl,and (2S,5S)-2,5-hexanediyl bis(4-vinylbenzoate)s as a model reaction for asymmetric cyclocopolymerization

The asymmetric cyclocopolymerization of bis(4-vinylbezoate) of a chiral diol with styrene is a promising method for the preparation of optically active polystyrene derivatives because of main-chain chirality. However, the mechanism for chirality induction from the chiral diol to the main chain is still unknown. To clarify the chirality induction mechanism, we carried out the radical cyclizations of (2S,3S)-2,3-butanediyl bis(4-vinylbenzoate), (2S,4S)-2,4-pentanediyl bis(4-vinylbenzoate), and (2S,5S)-2,5-hexanediyl bis(4-vinylbenzoate) with tri-n-butyltin hydride or allyltri-n-butyltin as a chain-transfer reagent as model reactions for asymmetric cyclocopolymerization. The absolute configuration was determined with single-crystal X-ray crystallography and a circular dichroism exciton chirality method. The distribution of the stereoisomer showed (R)-configuration selectivity (21–34% diastereomeric excess) in the intramolecular cyclization and an extremely low extent (<1%) of the (S,S)-cyclized product among the four stereoisomers. Therefore, chirality induction is caused by the selective inhibition of the (S,S)-racemo configuration. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4671–4681, 2004     

Synthesis and reactions of 2-[α-(3,4-disubstituted phenacyl)-p-substituted styryl]-4H-3,1-benzoxazin-4-ones

Science Department, Faculty of Teachers, P.O.Box 2313, Al Hasa, 31982, Saudi Arabia Faculty of Engineering, Ain Shames University, EgyptChemistry Department, Faculty of Science, Ain Shames University, Egypt     

Synthesis of 1,2-dihydroxyindolizidines from 1-(2-pyridyl)-2-propen-1-ol

1-(2-Pyridyl)-2-propen-1-ol, obtained by vinylation of commercially available picolinaldehyde, resulted a good starting material for the synthesis of the indolizidine skeleton. In particular, a simple process involving bromination, reduction, and nucleophilic substitution (via elimination and addition) allowed an easy conversion of the starting material into (±)-lentiginosine in ~27% overall yield.     

自由基链式亲核取代反应(S_(RN)1)的进展

本文评述了自由基链式亲核取代反应的最近进展。内容包括:脂肪族化合物和芳香族化合物按S_(RN)l进行的反应及其机理。     

2-苯基-1-(4-(1-吡咯乙氧基)苯基)乙酮的合成

2-苯基-1-(4-(1-吡咯乙氧基)苯基)乙酮是合成抗骨质疏松药拉索昔芬重要的结构片段。以苯酚为原料经成醚,磺酰氯酯化得到磺酸酯,然后经亲核取代反应,傅-克酰基化反应高收率地合成了目标化合物,其结构通过NMR和HRMS进行了表征。     

2－异丙基－1，3－二氢－4（1H）异喹啉酮及其衍生物的合成

异喹啉酮（1）与羟胺反应得异喹啉酮肟（2），再经Schroeter重排合成得到 4-氨基异喹啉的盐（3），进而经催化加氢还原生成其脱烷基产物6.另外 ，异喹啉 酮与NaN3反应合成得到苯并二氮杂Zhuo酮（4），4经还原可生成苯并二氮杂Zhuo（ 5），合成得到的5个新化合物的结构经元素分析、红外、^1H NMR及质谱等方法所 证实。     

2,3－二甲基－4－甲氧甲酰－2－环己烯醇的合成

2;3－二甲基－4－甲氧甲酰－2－环己烯醇的合成;二甲基甲氧甲酰环己烯醇;甲基甲氧甲酰环己烯酮;二甲基甲氧甲酰环己烯酮;氢化钠;氢化三叔丁氧基铝锂     

Synthesis of Novel Nucleoside Analog （3R）-2,3-Dideoxy-3-（N-hydroxy-N-methylamino）-L-arabinofuranosyl Uracil

The synthesis of novel nucleoside analog (3R)-2,3-dideoxy-3-(N-hydroxy-N-methylamino)-L-arabinofuranosyl uracil was studied. A twelve-step synthetic route, started from L-ascorbic acid, was designed, and the final product was obtained in 20.8% yield.     

Synthesis of Thiazino- and Thiazoloquinazolinones by Cyclization of S-(2-Propenyl) Derivatives of 2-Thioxo-2,3-dihydro-4(1H)-quinazolinone

Interaction of potassium salts of quinazolin-2-thiol-4-one with -substituted allyl halides gave thiazoloquinazolinones with linear or angular structures depending on the structure of the carbonyl radical. S-Allyl substituted quinazolin-2-thiol-4-one reacted with halogens to give iminium salts of thiazinoquinazolinone with an angular structure. The conversion of these salts to the corresponding bases and thiazoloquinazolinones has been studied.     

Short Synthesis of 1-(3-tert-Butyl-1-phenyl-1H-pyrazol-5-yl)-3-(5-(2-morpholinoethoxy)-2H-chromen-8-yl) Urea Derivatives

A short and efficient synthesis of 1-(3-tert-butyl-1-phenyl-1H-pyrazol-5-yl)-3-(5-(2-morpholinoethoxy)-2H-chromen-8-yl) urea derivatives (1a–c), a novel type of p38 MAPK inhibitors, is described. The Claisen thermal rearrangement of arylpropargyl ethers was employd as a key step to synthesize the chromene core. The solvent effect on the ratio of the resultant two isomers of Claisen thermal rearrangement, namely 2-methylbenzofuran and 2H-chromen, was also investigated.