氨基酸酯-烷基醚混合取代聚膦腈的合成与表征

聚膦腈高聚物,因其良好的生物相容性而用作生物医用材料。若在其侧链引入对热(如烷氧基醚)或对pH值敏感和可生物降解的基团(如氨基酸酯),则可得到具有环境敏感性和可生物降解性能的高聚物,这些高聚物可望作为药物载体,用于药物的控制释放。     

dl-六甲基化丹酚酸A甲酯的合成

以2,3二-甲氧基苯甲醛为原料,经还原、溴化、Wittig反应、在正丁基锂作用下醛基化、Knoevenagel反应生成四甲基化丹酚酸F(9),9再与草酰氯反应成酰氯后与甲基化丹参素甲酯反应得到dl-六甲基化丹酚酸A甲酯,其结构经1HNMR和MS表征,总收率44.7%。     

新型齐墩果酸糖苷化衍生物的合成及体外抗HCT8活性

为提高齐墩果酸的水溶性和稳定性,以齐墩果酸苷元为起始原料,对其28-COOH进行甲基化修饰后制得齐墩果酸-28-羧甲酯(1)。分别以D-半乳糖、D-葡萄糖、D-氨基葡萄糖为起始原料,通过对糖羟基的保护与去保护,得到一系列的二糖、四糖片段。通过三氯乙酰亚胺酸酯途径和对甲苯硫基途径,利用合成的糖片段对1的3-位羟基进行糖化学结构修饰,合成了4种新型的齐墩果酸糖苷化衍生物(2~5),其结构经1H NMR,13C NMR和MS(ESI)表征。采用MTT法测试了2~5对高表达人结肠癌细胞(HCT8)的体外抑制活性。结果表明:2~5对HCT8有一定的抑制作用,化合物5浓度为1×10^-3 mmol/L时,抑制率达到(98.96±0.10)%。     

Structure of poly(L‐lactic acid)s prepared by the dehydropolycondensation of L‐lactic acid with organotin catalysts

The synthesis of low‐molecular‐weight (weight‐average molecular weight < 45,000 g/mol) lactic acid polymers through the dehydropolycondensation of L ‐lactic acid was investigated. Polymerizations were carried out in solution with solvents (xylene, mesitylene, and decalin), without a solvent using different Lewis acid catalysts (tetraphenyl tin and tetra‐n‐butyldichlorodistannoxane), and at three different polymerization temperatures (143, 165, and 190 °C). The products were characterized with differential scanning calorimetry, size exclusion chromatography, vapor pressure osmometry, ¹³C NMR, and matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF). The resulting polymers contained less than 1 mol % lactide, as shown by NMR. The number‐average molecular weights were calculated from the ratio of the area peaks of ester carbonyl and carboxylic acid end groups via ¹³C NMR. The stereosequences were analyzed by ¹³C NMR spectroscopy on the basis of triad effects. Tetraphenyl tin was an effective transesterification catalyst, and the randomization of the stereosequence at 190 °C was observed. In contrast, the distannoxane catalyst caused comparatively less transesterification reaction, and the randomization of the stereosequences was slow even at 190 °C. The L ‐lactic acid and D ‐lactic acid isomers were added to the polymer chain in a small, blocky fashion. The MALDI‐TOF spectra of poly(L ‐lactic acid) (PLA) chains doped with Na⁺ and K⁺ cations showed that the PLA chains had the expected end groups. The MALDI‐TOF analysis also enabled the simultaneous detection of the cyclic oligomers of PLA present in these samples, and this led to the full structural characterization of the molecular species in PLA. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2164–2177, 2005     

天然环酯肽Obyanamide的全合成

针对目标化合物Obyanamide的结构特征, 运用反合成设计, 将其切为四个合成片断: N-甲基缬氨酸-N-甲基苯丙氨酸二肽(片断A)、噻唑酸衍生物(片断B)、L-乳酸衍生物(片断C)和β-氨基戊酸衍生物(片断D), 并对各个合成片断进行了合成, 最终顺利完成了对天然海洋环酯肽Obyanamide的全合成. 其化学结构经¹H NMR, ¹³C NMR, HMBC以及HRMS (FAB)予以确证.     

N-茄呢基谷氨酰胺类化合物的合成

在N,N 二环己基碳二酰亚胺存在下,N 苯甲酰 Nα 茄呢基 L 谷氨酰胺酸和N 羟基琥珀酰亚胺反应制成活化酯,然后分别与胺或者氨基酸甲酯盐酸盐反应制得3种新N 茄呢基谷氨酰胺类化合物.这些化合物的结构经IR、1HNMR、MS和元素分析确证.     

合成1,2-环十二二酮的新方法

以十二烷二酸（１）为原料,与甲醇酯化生成十二烷二酸二甲酯（２）,收率为８６５％。化合物２经偶联 缩合得１,２ 二三甲基硅氧基环十二烯（３）,收率为６３１％。利用溴氧化化合物３得到１,２ 环十二二酮（４）淡黄色晶体,收率７９％,全过程收率达４３.１％,是合成１,２ 二酮的新方法。目标化合物结构经红外光谱、核磁共振氢谱和碳谱表征确认。     

"一锅法"合成叔胺

以氨基酸甲酯的盐酸盐为原料,用“一锅法”高产率地合成了一系列N-取代叔胺,其结构经1H NMR和MS表征。     

5－依维菌素B_(1a)酯的合成和生物活性

依维菌素B_(1a)与羧酸在DMAP/DCC体系中直接酯化，得到10个5-IV B_(1a)酯 衍生物，产率66%～82%；它们的化学结构得到IR，~1H NMR, ~(13)c nmr和MS谱的 确证。它们具有良好的杀虫、杀螨活性。     

不同Ｎａ／Ｐ比磷酸钠盐催化剂对乳酸转化反应的影响

将NaH2PO4与不同比例的Na2CO3或H3PO4混合,通过浸渍法负载在硅胶上,经过焙烧,制备了Na/P比不同的磷酸钠盐催化剂.利用所制备的催化剂考察了乳酸生成丙烯酸的脱水反应.运用XRD、Raman以及31PNMR等手段对所制备的催化剂结构进行了表征,并使用NH3-TPD对磷酸钠盐催化剂的酸强度和酸性位密度进行了测量.结合催化剂的结构表征结果,对磷酸钠盐的表面酸性进行了探讨.基于磷酸钠催化剂的结构和酸性,讨论了它们的催化性能.     

叶绿素-a及其衍生物的Qy轴向氧化反应和E-环重排反应

在酸碱性条件下对叶绿素-a (1)进行空气氧化反应, 分别得到卟吩衍生物2b～4b; 通过酯交换和去金属镁离子, 将叶绿素-a转化为脱镁叶绿酸-a甲酯(MPa) (5), 其3-位碳碳双键与氯化氢的加成生成卟吩醇(6), 经碱性空气氧化和E-环重排则转化成紫红素-18衍生物7. 选用四氧化锇和高碘酸钠将5氧化成卟吩醛(8), 在丁醇中以丁醇钠作催化剂, 8的氧化和重排反应给出3-甲酰基紫红素-18酯(9)和紫红素-7三甲酯衍生物10. 异构体4的空气氧化和重排反应也生成紫红素-18酯(3), 进一步与2-甲基丁胺进行缩合反应, 得到N-烷基紫红素-18酰亚胺(11a)以及氧化重排产物3-甲酰基-N-烷基紫红素-18酰亚胺(11b). 所得叶绿素衍生物均经UV, IR, 1H NMR及元素分析证明其结构, 并对相应的反应提出可能的反应机理.     

新型含氨基酸官能团的香豆素衍生物的合成

以L-苯丙氨酸、L-色氨酸、L-酪氨酸和组氨酸为原料,在Me₃SiCl-MeOH(Ⅲ)体系中反应合成了相应的甲酯盐酸盐（2a~2d）;以7-羟基香豆素为原料,经两步反应制得7-(乙酸氧基)香豆素（6）; 6与3a经酰胺化反应合成了一种新型的香豆素衍生物--N-乙酰基-(氧-7-香豆素)-3-苯基-2-氨基-丙酸甲酯,其结构经¹H NMR, ¹³C NMR和FT-IR表征。     

Performance testing of a green plasticizer based on lactic acid for PVC

In order to develop alternative green plasticizers, a bio-based plasticizer, acetylated lactic acid 1,4-cyclohexanedimethyl ester(ALCH), with novel molecule geometry was synthesized from l-lactic acid and characterized by FTIR, ¹H NMR and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). The prepared ALCH was mixed with poly(vinyl chloride) (PVC) as plasticizer and the results indicated that the PVC films plasticized by ALCH have better migration and volatility stability than acetyl tributyl citrate (ATBC). In addition, ALCH could endow PVC products with excellent performance of strength, elongation and elasticity. With the substitution of ALCH for ATBC, glass transition temperature (Tg) of PVC films decreased gradually from 61.3°C to 55.0 °C. The self-polymerization of lactic acid gives ALCH better plasticizing effectiveness than ATBC.     

EPA甲酯和DHA甲酯标准样品的制备和结构解析

从鱼油中分离制备得到二十碳五烯酸（EPA）甲酯和二十二碳六烯酸（DHA）甲酯,采用红外光谱、质谱、核磁共振波谱等手段对EPA甲酯和DHA甲酯的结构进行表征,提供了不饱和脂肪酸甲酯标准物质研制基础。样品的红外光谱（IR）、质谱（MS）、核磁共振谱图（1HNMR、13CNMR）所给出的结构信息与EPA甲酯和DHA甲酯的化学结构式相符,并通过DEPT谱和I3C-1H COSY化学位移相关谱（HMBC）对各共振峰进行了指认,样品的谱图数据与文献报道基本一致。     

Synthesis and Characterization of Amphiphilic Biodegradable Copolymer,Poly(aspartic acid‐co‐lactic acid)

An amphiphilic biodegradable polymer, poly(aspartic acid‐co‐lactic acid) (PAL), was synthesized by simply heating a mixture of aspartic acid (Asp) and L ‐lactide without additional catalysts or solvents. The unique branched architecture comprising succinimide units and lactic acid units was confirmed by IR and NMR spectroscopy. A copolymer of sodium aspartate and lactic acid (PALNa) was prepared by reacting PAL with an aqueous sodium hydroxide solution. The PAL was soluble in many organic solvents, while the PALNa was soluble in methanol and water. The hydrolytic degradation behavior of PAL varied with the copolymer composition. A higher Asp content resulted in a faster molecular weight decrease, and introducing glycolic acid units accelerated the degradation rate.

Microphotograph of microsphere of PAL‐1/5.     

胡椒酸己二胺的合成

以胡椒碱为起始原料,与KOH反应生成胡椒酸钾盐,经酸化后制得胡椒酸(2); 2与乙醇经酯化反应制得胡椒酸乙酯(3); 3与己二胺在金属钠催化下经氨解反应合成了胡椒酸己二胺(4),其结构经¹H NMR, ¹³C NMR和IR确证。合成4的最佳反应条件为：催化剂用量2 wt%, n(3):n(己二胺)=0.6, m(乙醇):m(3)=2.5,于65～75 ℃反应48 h,收率83.5%。该工艺在微型实验基础上放大十倍,收率大于79%。     

4-氯-1,7-二羟基二氢化茚的合成及意外醚化反应的研究

以对氯苯酚(8)为原料、三乙胺作缚酸剂，与丙烯酰氯反应生成对氯苯酚丙烯 酸酯(7)，7与A1Ck共热155℃，首先发生Fries重排，然后关环得到4-氯-7-羟基二 氢化茚-1-酮(6)，再用NaBHl／CH_3OH或LiAlH_4／THF还原6的羰基得到4-氯-1，7- 二羟基二氢化茚(5)．条件控制不当易产生两个意外的醚化产物4-氯-1-甲氧基-7- 羟基二氢化茚(9)和自身醚化产物10，9的结构经x射线单晶衍射分析确证，并提出 生成10的可能机理为5的醇羟基极易通过分子内催化形成碳正离子、进而与另一分 子5形成自身醚化产物10．因此，还原反应完成后的后处理应避免长时间放置和加 热，以减少醚化产物的生成．化合物5，9，10均为未见文献报道的新化合物．     

Chromatographic separation of diastereoisomeric esters-II Mandelates and lactates of 2-methylbutanol-1, 3-methylbutanol-2, pentanol-2 and hexanol-2

The racemic alcohols, 2-methylbutanol-l, 3-methylbutanol-2, pentanol-2 and hexanol-2 have been esterified with optically active mandelic or lactic acid, and the resultant mixtures of diastereoisomeric esters separated chromatographically with an optically inactive sulphonated polystyrene resin as the stationary phase and water or dilute aqueous sodium sulphate as the mobile phase. Lactate esters were more easily separated than mandelate esters. The Chromatographic separation of 26 mmole of (+/-)-3-methyl-2-butyl(+)-lactate and subsequent hydrolysis of the fractions containing only the ester of the (+)-alcohol yielded 1-2 mmole of pure 3-methyl-2-butanol.     

双水相体系中Proline/CuI催化Heck反应的研究

以双水相为反应溶剂,丙烯酸酯、苯乙烯与多种芳卤化合物在催化剂碘化亚铜、配体L-脯氨酸的存在下,在较低的温度(75～85 ℃)下得到了产物,该方法具有反应时间短、产率较高、选择性较好等特点,为该反应及该类化合物的合成提供了一种新方法。产物通过熔点、红外、核磁共振氢谱、碳谱等方法的表征。     

Synthesis of chiral linear and macrocyclic candidates: VI. Synthesis and antibacterial activity of some macrocyclic tripeptides and linear dipeptide Schiff bases

A series of macrocyclic tripeptides and linear dipeptide Schiff base derivatives has been synthesized using pyridine-3,5-dicarboxylic acid and L-phenyalanine methyl ester as starting materials. Treatment of pyridine-3,5-dicarbonyl dichloride with L-phenylalanine methyl ester gave N,N′-(pyridine-3,5-diyldicarbonyl)bis(L-phenyalanine methyl ester) which was hydrolyzed with 1N sodium hydroxide to the corresponding bis-acid, and the latter was cyclized with diamino acids to afford macrocyclic tripeptide derivatives. The reaction of the bis ester with hydrazine hydrate gave bis-hydrazide, which was condensed with aldehydes to obtain the corresponding Schiff base derivatives. The structures of the newly synthesized compounds were confirmed by IR, ¹H and ¹³C NMR, and MS spectral data and elemental analyses. The antimicrobial activities of some of the newly synthesized compounds were comparable with that of Streptomycin used as control.