3-(2-羟基苯基)-5-苯基-6-乙氧羰基-2-环己烯酮的合成与晶体结构

合成了3-(2-羟基苯基)-5-苯基-6-乙氧羰基-2-环己烯酮.通过元素分析、红外光谱、紫外光谱、核磁共振氢谱和质谱对其组成和结构进行了表征.利用X射线衍射分析方法测定了它的晶体结构.该化合物的晶体属单斜晶系,空间群P21/c,a=1.41946(17)nm,b=0.58445(7)nm,c=2.1756(3)nm,β=104.795(2)°,V=1.7450(4)nm3,Z=4,Dc=1.280 g·cm-3,F(000)=712,μ=0.088mm-1,R1[I＞2σ(I)]=0.0627,wR2[I＞2σ(I)]=0.1484.晶体结构测定结果表明化合物分子中的环己烯部分为半椅式构象,分子间通过氢键形成具有16元环的二聚体.     

3-羟基-1-(2,6,6-三甲基-3-环己烯基)-1-丁酮的合成及其向卷烟烟气释放δ-突厥酮的研究

以亚异丙基丙酮,1,3-戊二烯为原料经Diets-Alder反应合成了4-乙酰基-3,5,5-三甲基环己烯(4),4再与乙酸乙酯在乙醇钠的存在下缩合得到1-(2,6,6-三甲基-3-环己烯-基)-1,3-丁二酮(5),5用硼氢化钠还原合成了3-羟基-1．(2,6,6-三甲基-3-环己烯基)-1-丁酮。其结构经GC—MS和^1H NMR证实。将此目标化合物用作香料成分加入卷烟,用GC—MS检测其烟气成分,发现此化合物在卷烟燃吸时能发生裂解反应,向烟气释放具有致香作用的δ-突厥酮。     

3-甲基-4-乙氧甲酰-2-环己烯酮合成方法的改进

甲基乙氧羰基环己烯酮;多聚甲醛;3-甲基-4-乙氧甲酰-2-环己烯酮合成方法的改进     

Ru-[bmim]BF4 的制备及催化苯选择加氢反应性能

以离子液体1-丁基-3-甲基咪唑四氟硼酸盐([bmim]BF4)-水混合溶剂为介质,采用化学还原法制备了Ru-[bmim]BF4催化剂,并利用紫外-可见光谱、红外光谱、透射电镜、X射线衍射和X射线光电子能谱对催化剂进行了表征.结果表明,Ru在[bmim]BF4中分散较好,粒径~2nm,且离子液体中咪唑阳离子与部分Ru形成了金属卡宾配合物.利用苯选择加氢反应对该催化剂性能进行了评价,发现Ru-卡宾配合物存在时,催化剂活性较低,但环己烯选择性较高.在本文反应条件下,苯转化率为12.2%,环己烯选择性为40.5%.重复使用该催化剂时,由于Ru-卡宾配合物在反应中转变为Ru0,其催化活性增加,但环己烯选择性下降.继续多次使用该催化剂,其性能基本保持稳定.     

含2-取代-1,3-二硫杂环戊烷的大环席夫碱的合成、表征及其生物活性研究

以不同的β-二酮、二硫化碳、1,2-二溴乙烷等为原料合成含2-取代-1,3-二硫杂环戊烷的大环席夫碱化合物,进行了初步抗菌活性研究。合成得到的中间体（Ia～Ic）及目标化合物（IIa～IIc）的结构由元素分析、红外光谱、1H NMR、MS等得到确证。抗菌试验结果表明,合成得到的大环席夫碱对枯草杆菌、大肠杆菌、金黄色葡萄...     

聚(1,4-环己二烯碳酸酯)立体低聚物的合成及微结构分析

聚合物微结构控制是配位催化聚合领域最重要的目标之一.而合成各种立构规整性低聚物及其核磁碳谱研究是聚合物微结构定性和定量分析的关键.本文以手性环己-4-烯-1,2-二醇为原料,采用N,N'-羰基二咪唑和三光气作为羰化试剂,设计合成了CO_2/1,2-环氧-4-环己烯交替共聚物(聚(1,4-环己二烯碳酸酯),PCEC)全同立构和间同立构的二聚体、四聚体、六聚体、八聚体和十二聚体模型化合物.通过分析全同立构和间同立构模型化合物的核磁碳谱,完成了PCEC微结构的碳谱信息归属.发现聚合物全同立构序列的羰基、次甲基和亚甲基区域的出峰位置分别在δ=154.04、73.83和29.91;间同立构序列的羰基、次甲基和亚甲基区域的出峰位置分别在δ=153.72、72.97和28.98.     

冷柱头程序升温进样-气相色谱/质谱法研究新鲜大蒜中的有机硫化合物

采用冷溶剂提取新鲜大蒜中的有机硫化合物,结合冷柱头程序升温进样,对大蒜原始组分进行了气相色谱/质谱分析 。该法实现了从提取到色谱分离的“冷过程”,因而可以准确地鉴定大蒜提取液在热分解前的原始组分。分析结果表明, 在大蒜提取液中含有3-乙烯基-1,2-二硫杂-5-环己烯及其异构体2-乙烯基-1,3-二硫杂-4-环己烯两种主要组分以及少量 的S-甲基甲烷硫代亚磺酸酯、二烯丙基二硫醚、二烯丙基三硫醚。对大蒜的冷溶剂提取液和水蒸气蒸馏提取的大蒜油中 的有机硫化合物进行了比较,对一些主要有机硫化合物的形成进行了初步探讨。     

阳离子交换树脂/H_2O_2体系催化氧化环己烯的研究

在以改性阳离子交换树脂为催化剂、H2O2为氧化剂的催化氧化体系中,主要研究和考察了环己烯直接氧化制备1,2-环己二醇的反应,并优化得到了最佳合成工艺,在无溶剂,H2O2与环己烯的摩尔比为1.0:1.0、反应温度为70℃、反应时间为6.5h、催化剂用量为环己烯摩尔量10%的反应条件下,环己烯的转化率大于99.0%,产品1,2-环己二醇的选择性大于98.0%。阳离子交换树脂催化剂重复使用12次未见其活性和选择性明显下降。在此反应条件下,直链状的1-己烯也可高效和高选择性地转化为1,2-己二醇。     

第23届全国高中学生化学竞赛实验试题

顺-4-环己烯-1, 2-二羧酸的制备及纯度分析 一、实验内容 1. 产品制备:先由环丁烯砜和顺丁烯二酸酐反应得到顺-4-环己烯-1, 2-二酸酐(用A表示),再水解得到产品顺-4-环己烯-1, 2-二羧酸(用B表示). 2. 产品纯度分析:通过酸碱滴定法测定自制产品B的纯度.     

(4R-cis)-6-[2-[2-(4-氟苯基)-5-(1-异丙基)-3-苯基-4-[苯胺(羰基)]-1 H-吡咯-1-基]乙基]-2,2-二甲基-1,3-二氧己环-4-乙酸叔丁酯的波谱学研究

对(4R-cis)-6-[2-[2-(4-氟苯基)-5-(1-异丙基)-3-苯基-4-[苯胺(羰基)]-^1H-吡咯-1-基]乙基]-2,2-二甲基-1,3-二氧己环-4-乙酸叔丁酯的傅里叶变换离子回旋共振质谱(FT-ICR-MS)、核磁共振氢谱(^1H-NMR)、碳谱(^13C-NMR)以及^1H同核位移相关谱(^1H-^1HCOSY)、检出^1H的异核多量子相干谱(HMQC)和^1H检测的异核多键相关谱(HMBC)报道并进行解析。确定了^1H谱、^13C谱中各谱峰的归属,研究了其六元环部分的立体构象,并就空间效应对其化学位移的影响做了初步的探讨。     

An azomethine ylide approach to complex alkaloid-like heterocycles

The nitrone above is readily available via the intramolecular aza Diels-Alder reaction of an amino acid derived triene in acetic acid. Subsequent treatment of the nitrone in refluxing toluene with substituted actetylenes produced the pictured pyrrole. At lower temperatures a 2,3-dihydroisoxazole, which is the product of a 3+2 dipolar cycloaddition, is produced. Upon heating in refluxing toluene the 2,3-dihydroisoxazole is converted to the pyrrole.     

A total synthesis of the epoxyquinone based antifungal natural product (±)-ambuic acid

A total synthesis of the recently isolated polyketide natural product (±)-ambuic acid has been accomplished from the readily available Diels-Alder adduct of cyclopentadiene and 2-allyl-p-benzoquinone through a simple sequence with sound stereocontrol.     

Sequential aminodiene Diels-Alder approach to the ergoline skeleton

Through a novel sequence of aminodiene Diels-Alder reactions, several substituted amidofurans were readily converted to tricyclic ketones in good yield. The formation of the tricyclic ketone system is the result of a ring opening and dehydration of a transient oxabicyclic adduct formed by an intramolecular Diels-Alder cycloaddition of an amidofuran with a cyclohexenone moiety tethered such that it participates in the cycloaddition as the 2pi component. A convenient way to construct the cyclohexenone is to make use of some aminodiene chemistry developed by Rawal. An angular carbomethoxy group is required in order to activate the olefin toward cycloaddition with Rawal's diene. The presence of this activating group not only prevents the isomerization of the advanced ergoline intermediate to a naphthalene but can also be leveraged for an oxidation to provide Uhle's ketone (13). The easily formed Kornfeld ketone analogue 25 was readily transformed into the corresponding triflate 41 by the action of triflic anhydride and a base. Oxidative addition of vinyl triflate 41 to Pd(0) and the ability of the resulting vinyl palladium species to undergo cross-coupling with terminal alkynes prompted us to devise an expeditious route to lysergic acid. Unfortunately, our inability to carry out a regioselective Heck reaction using vinyl triflate 41 and the methylene amino acrylate ester 48 thwarted the completion of the synthesis of lysergic acid.     

Total synthesis of the novel, biologically active epoxyquinone dimer (+/-)-torreyanic acid: a biomimetic approach

[reaction: see text] A total synthesis of the complex, biologically active, dimeric natural product (+/-)-torreyanic acid, which is composed of seven rings and laced with dense, variegated oxy-functionalization, has been accomplished from readily available allyl-substituted p-benzoquinone 8. Our synthetic stratagem involves crafting an epoxyquinone monomer for use in a biomimetic cascade process involving tandem a 6pi electrocyclization and a Diels-Alder dimerization.     

Synthesis and Diels-Alder reactions of homochiral 2-sulfinylmaleates with cyclopentadiene

Enantiomerically pure 2-p-tolylsulfinylmaleates 1, 2 and 3 have been readily prepared by Knoevenagel reaction between (S)-menthyl p-toluenesulfinate and glyoxylic acid. Their asymmetric Diels-Alder reactions with cyclopentadiene have been studied under a wide range of uncatalyzed and catalyzed conditions and the stereochemical results have been explained by assuming a steric control approach, in term of S-cis or S-trans favoured conformations. Uncatalyzed Diels-Alder reactions of 1 and some Lewis acid catalyzed Diels-Alder reactions of 2 show high facial and endo selectivities. The facial selectivity of dienophile 2 highly depends on the Lewis acid, whereas reactivity of 1 and 3 is very sensitive to the solvent. These sulfinylmaleates 1, 2 and 3 act as synthetic equivalents of chiral acetylenedicarboxylates in Diels-Alder reactions after basic elimination of the sulfinylic moiety in the resulting adducts.     

Enhancing the scope of the Diels-Alder reaction through isonitrile chemistry: emergence of a new class of acyl-activated dienophiles

α,β-Unsaturated imides, formylated at the nitrogen atom, comprise a new and valuable family of dienophiles for servicing Diels-Alder reactions. These systems are assembled through extension of recently discovered isonitrile chemistry to the domain of α,β-unsaturated acids. Cycloadditions are facilitated by Et(2)AlCl, presumably via chelation between the two carbonyl groups of the N-formyl amide. Applications of the isonitrile/Diels-Alder logic to the IMDA reaction, as well as methodologies to modify the N-formyl amide of the resultant cycloaddition product, are described. It is expected that this easily executed chemistry will provide a significant enhancement for application of Diels-Alder reactions to many synthetic targets.     

Stereoselective synthesis of the cis-275B decahydroquinoline ring system

The Diels-Alder precursor was constructed from readily available d-glutamic acid utilizing a series of functional group transformations. The stereocenter of the amino acid provided the desired stereochemistry at C2 and diastereoselectively directed the intramolecular Diels-Alder cyclization. This simultaneously generated the three remaining stereocenters and yielded a bicyclic intermediate with all four stereocenters of the target decahydroquinoline 275B.     

Valence-bond isomer chemistry. Part 11 [1]. Thermal rearrangement of the Diels-Alder adduct of hexafluorobicyclo-[2.2.0]hexa-2,5-diene and 2,3-Dimethylbuta-1,3-diene: a [1,3] sigmatropic shift of fluorine

Flow pyrolysis of the Diels-Alder adduct of hexafluorobicyclo[2.2.0]hexa-2,5-diene and 2,3-dimethylbutadiene gives an unusual product, the Diels-Alder adduct of hexafluorobenzene and 2,3-dimethylbuta-1,3-diene, and thence via an exclusive [1,3] sigmatropic fluorine shift, its isomeric triene. Loss of hydrogen fluoride from the unusual Diels-Alder adduct readily affords 1,2,3,4-tetrafluoro-6,7-dimethylnaphthalene.     

Synthesis of a novel bicyclic scaffold inspired by the antifungal natural product sordarin

A simplified bicyclic scaffold inspired by the antifungal natural product sordarin was designed and synthesized which maintains the carboxylic acid/aldehyde (or nitrile) pharmacophore. Docking studies with the target for sordarin, the fungal protein eukaryotic elongation factor 2 (eEF2), suggested that the novel scaffolds may bind productively. A densely functionalized chiral cyclopentadiene was constructed in 8 steps and utilized in a Diels-Alder reaction with acrylonitrile. The resulting [2.2.1] cycloheptene was transformed into a scaffold possessing vicinal carboxylic acid and nitrile groups, with orientations predicted to provide high affinity for eEF2. The synthetic approach disclosed here sets the stage for a renewed medicinal chemistry campaign against eEF2.