对萘普生和萘普生甲酯的毛细管电泳手性分离

以磺化β－ＣＤ作为手性分离添加剂,分别对萘普生和萘普生甲酯进行了手性分离研究,当磺化β－ＣＤ的浓度为３．５％（Ｗ／Ｖ）时,萘普生和萘普生甲酯的手性分离度都可大于２,但萘普生与萘普生甲酯不能达到同时拆分。如果同时以磺化β－ＣＤ和ＨＰ－β－ＣＤ作为作为手性分离添加剂,则可对萘普生甲酯达到同时拆分,当磺化β－ＣＤ和ＨＰ－β－ＣＤ的浓度分别为３．５％和１．５％（Ｗ／Ｖ）时,对萘磺生和萘普生甲酯两种消旋体的     

膜反应器中萘普生甲酯的动态拆分

在碱催化连续原位消旋条件下,利用CRL脂肪酶（Candida rugosa lipase）催化的萘普生甲酯立体选择性水解反应。动态拆分制备（S）－普生。使用硫水硅橡胶膜隔离生物催化拆分反应和碱催化消旋反应,解决了常规动态拆分反应中生物催化剂难以承受原位化学消旋苛刻反应条件的难题。为了利于从水－有机溶剂乳化体系中分离产物和克服产物抑制,将亲水半透膜引入搅拌罐反应器,在该膜反应器中进行动态拆分反应。当转化率超过60％时,产物（S）－萘普生的对映体过量值（eep)仍在96％以上,在反应过程中还发现CRL脂肪酶同工酶的转化。     

Densitometric Determination of Naproxen,and of Naproxen Methyl Ester,its Impurity,in Pharmaceutical Preparations

JPC – Journal of Planar Chromatography – Modern TLC - A chromatographic–densitometric method has been established for identification and quantification of...     

A Convenient Method for Synthesis of Gem-bromochlorocyclopropanes

Gem-bramochlorocyclopropanes can be prepared by a convenient method based on the reaction of the mixtures of haloforms and tetrahalomethanes or hexahaloethane with powdered sodium hydroxide.     

S-2-(苄氧羰基)氨基-6-(三苯甲基)巯基-正己酸甲酯的简便合成

以L-赖氨酸为原料研究了新化合物S-2-（苄氧羰基）氨基-6-（三苯甲基）巯基．正己酸甲酯的合成,合成的总收率为27％．该方法简便高效,同时可作为半胱氨酸同系物的通用合成方法．     

水饱和离子液体中脂肪酶催化萘普生甲酯对映选择性水解

 对比研究了水饱和异辛烷和水饱和离子液体1-正丁基-3甲基咪唑六氟磷酸盐([bmim]PF6)中脂肪酶催化萘普生甲酯不对称水解反应. 结果表明,由于离子液体[bmim]PF6同时具有极性和疏水性,因而成为萘普生甲酯不对称水解反应的理想介质. 与水饱和异辛烷相比,水饱和离子液体不仅明显降低了水解反应的平衡常数(K),增大了对映体比率(E),从而有效提高了水解反应的平衡转化率(ceq)和产物的对映体过量值(eep),而且由于离子液体对另一产物甲醇的溶解度高,还明显地提高了脂肪酶的操作稳定性.     

A Practical Synthesis of 6-Acetylsalicylic Acid Methyl Ester

A new and efficient synthesis of the title compound is reported. The method includes a regioselective ortho-lithiation step in none polar solvents at an ambient temperature and the overall yield for 5 steps is more than 70% from a commercially available 3-hydroxyacetophenone.     

A Total Synthesis of Spirastrellolide A Methyl Ester

A concise total synthesis of spirastrellolide A methyl ester ( 1 a , R¹=Me) as the parent compound of a series of highly cytotoxic marine macrolides is disclosed, which exploits and expands the flexibility of a synthesis plan previously developed by our group en route to the sister compound spirastrellolide F methyl ester ( 6 a , R¹=Me). Key to success was the masking of the signature Δ^15,16‐bond of 1 a as a C16‐carbonyl group until after the stereogenic center at C24 had been properly set by a highly selective hydrogenation of the C24 exo‐methylene precursor 66 . Conformational control over the macrocyclic frame allowed the proper stereochemical course to be dialed into this reduction process. The elaboration of the C16 ketone to the C15–C16 double bond was accomplished by a chemoselective alkenyl triflate formation followed by a palladium‐catalyzed hydride delivery. The role of the ketone at C16 as a strategic design element is also evident up‐stream of the key intermediate 66 , the assembly of which hinged upon the addition of the polyfunctionalized dithiane 37 to the similarly elaborate aldehyde fragment 46 . Other crucial steps of the total synthesis were an alkyl‐Suzuki coupling and a Yamaguchi lactonization that allowed the Northern and the Southern sector of the target to be stitched together and the macrocyclic perimeter to be forged. The lateral chain comprising the remote C46 stereocenter was finally attached to the core region by a modified Julia–Kocienski olefination. The preparation of the individual building blocks led to some methodological spin‐offs, amongst which the improved procedure for the N–O‐bond cleavage of isoxazolines by zero‐valent molybdenum and the ozonolysis of a double bond in the presence of other oxidation‐prone functionality are most noteworthy. Preliminary biological data suggest that the entire carbon framework, that is the macrocyclic core plus the lateral chain, might be necessary for high cytotoxicity.     

A Convenient Method for the Synthesis of Aminomethylmonoalkylphosphinate

Starting from the readily available 4‐methylbenzoic acid, an efficient protocol for the preparation of ethyl 4‐(aminomethyl) benzyl (methyl) phosphinate ( 1 ), a novel aminomethylmonoalkylphosphinate was reported in this communication. The important step involves the selective monochlorination of phosphonic ester by POCl₃ and forming the phosphonochloridate, and followed by nucleophilic addition of CH₃MgBr to the acid chloride intermediate.     

Convenient Method for the Synthesis of N-(Ethyloxycarbonyl) Ester Derivatives from Amino Acids

Amino acids upon treatment with ethyl chloroformate in methanol in the presence of potassium carbonate give the corresponding N-(ethyloxycarbonyl) amino acid ester derivatives in good yields. These derivatives can be also synthesized by performing the reaction in THF in the presence of alcohols.     

A Convenient Method of N-Methylphthalimide Synthesis

We suggest a convenient method to obtain N-methyiphthalimide with a high yield in the reaction of phthalic anhydride with aqueous methylamine.     

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%。     

新的溶致液晶性高分子——N-马来酰化壳聚糖的合成与表征

新的溶致液晶性高分子——Ｎ┐马来酰化壳聚糖的合成与表征董炎明李志强（厦门大学化学系福建厦门３６１００５）壳聚糖（（１，４）－２－氨基－２－脱氧－β－Ｄ－葡聚糖）是甲壳素经脱乙酰化得到的一种生物高分子。它的原料是海产品加工厂的废料，因而来源十分丰富，作...     

"一锅法"合成戊二烯甲酯

以丙烯醛和丙二酸为原料,经缩合反应制得戊二烯酸,产率52．2％。采用“一锅法”合成了戊二烯酸甲酯,产率52．8％。其结构经^1H NMR和IR确证。     

A Convenient Method for the Synthesis of bis-Trifluoroethyl Phosphonoacetates

bis-Trifluoroethyl phosphonoacetates were easily obtained by condensation of bis-trifluoroethyl alkylphosphonates with alkyl chloroformates in the presence of 2 equivalents of lithium hexamethyldisilazane (LiHMDS).     

A Convenient Method for the Synthesis of Distamycin Analogue

A novel distamycin analogue was synthesized by chloroform reaction and DCC/HOBT coupling reaction without using amino protection and deprotection.     

苏型-N-苯甲酰基-3-苯基异丝氨酸甲酯的合成

紫杉醇;苏型-N-苯甲酰基-3-苯基异丝氨酸甲酯的合成     

Synthesis of 9-Deoxynanaomycin a Methyl Ester1

The tricyclic intermediate 6 prepared in three steps from 1,4-dimethoxynaphthalene was utilized in preparing alkene 7. Cleavage of the double bond of 7 furnished the keto aldehyde 9 which was transformed to the unsaturated ester 13. The ester 13 on heating with KOH-MeOH furnished the acid 14a whose methyl ester was oxidised to 9-deoxynanaomycin A methyl ester (2).