3-羰基-雄甾-4-烯-17β-酸的合成

以脱氢异雄酮(DHEA)为原料,经过Wittig反应、硼氢化-氧化反应、Oppenauer反应和Jone's氧化反应合成了重要甾体中间体3-羰基-雄甾4-烯-17β-酸,总收率达23.0%,并采用核磁、质谱和红外表征了产物结构.     

创新工艺

非那雄胺的合成 第二军医大学药学院的研究人员研究了非那雄胺的合成。他们以孕烯醇酮醋酸酯为原料,经次溴酸钠氧化、甲醇甲酯化得到3-羰基-4-雄甾体烯-17β羧酸甲酯,再经Oppenauer氧化、双键的氧化切断、氨解环合、双键加氧、1,2位脱氢、Bodroux反应等8步反应制得非那雄胺。结果表明：该方法原料易得、操作简单、成本低廉、收率高。     

由胆甾醇制备2-苯亚甲基-5α-胆甾烷-3-酮

以胆甾醇(■)为起始原料,通过10%Pd-C催化加氢还原合成5α-胆甾烷-3β-醇(■),■经Jones试剂氧化反应,得到5α-胆甾烷-3-酮(■),■经NaOH催化与苯甲醛发生Claisen-Schmidt缩合生成2-苯亚甲基-5α-胆甾烷-3-酮(■)。对制备工艺进行了优化,确定加氢反应的条件为:乙醇溶液中,25℃反应20 h;Jones试剂氧化反应的条件为:丙酮溶液中30℃反应2 h;Claisen-Schmidt缩合反应的条件为:乙醇溶液中,在NaOH催化下先25℃反应2 h,再升温至50℃反应3 h。优化条件下,3步反应总收率74.7%。产物结构经~1H NMR、~(13)C NMR和APCI-MS确证。     

5α-氯-6β-羟基-雄甾-3,17-二酮的合成

以4-雄烯二酮为原料,经羰基保护、双键卤羟化、水解脱保护三步反应合成了5α-氯-6β-羟基-雄甾-3,17-二酮。讨论了保护试剂、催化剂、卤羟化试剂、反应温度等对实验结果的影响,得出了较佳工艺条件,三步总收率达到88%。     

DMAP催化的17β-氰基-17α-羟基雄甾-4-烯-3-酮硅醚化反应研究

以4-二甲氨基吡啶(DMAP)为催化剂,氯甲基二甲基氯硅烷(CDCS)为硅醚化试剂,Et3N为缚酸剂,5℃反应2 h,对17β-氰基-17α-羟基雄甾-4-烯-3-酮(I)的17α-OH进行硅醚化保护,生成17β-氰基-17α-羟基雄甾-4-烯-3-酮-17-氯甲基二甲基硅醚(II)。研究水分、p H、DMAP用量及投料顺序对化合物(I)硅醚化反应的影响。在最佳反应条件下,化合物收率98.70%,纯度99.07%。     

DMAP催化的17β-氰基-17α-羟基雄甾-4-烯-3-酮硅醚化反应研究

以4-二甲氨基吡啶(DMAP)为催化剂,氯甲基二甲基氯硅烷(CDCS)为硅醚化试剂,Et3N为缚酸剂,5℃反应2 h,对17β-氰基-17α-羟基雄甾-4-烯-3-酮(I)的17α-OH进行硅醚化保护,生成17β-氰基-17α-羟基雄甾-4-烯-3-酮-17-氯甲基二甲基硅醚(II)。研究水分、p H、DMAP用量及投料顺序对化合物(I)硅醚化反应的影响。在最佳反应条件下,化合物收率98.70%,纯度99.07%。     

胆甾烷-3-醇及胆甾烷-3-酮的合成研究进展

甾族化合物在生物、医药等诸多方面具有很重要的利用价值.本文在大量文献的基础上对以胆固醇为原料,经还原反应制备胆甾烷-3-醇和以胆甾烷-3-醇为原料经氧化反应制备胆甾烷-3-酮的合成工艺进行了综述,重点对上述合成工艺的催化剂及催化方法进行了阐述,并分析了不同催化剂的优缺点,对今后的研究方向进行了归纳.     

Phytophthora α1性信息素C(9)～C(16)片段的合成

以甾体皂甙元氧化降解废弃物(R)-4-甲基-5-羟基戊酸甲酯为原料,经包括酯的格氏加成反应、烯烃的臭氧化反应和环氧化合物的亲核加成等六步反应,以60.5%的总收率合成得到了Phytophthora α1性信息素的C(9)~C(16)片段4。     

IBX选择性脱氢功能在制备非那雄胺中的应用

利用2-碘酰基苯甲酸(IBX)的选择性脱氢功能,在N-叔丁基-3-羰基-4-氮杂-5a-雄甾-17β-甲酰胺的1,2-位选择性脱氢,制备非那雄胺.产率可达92%.     

5a-雄甾-2-烯-17-酮的合成

以表雄酮为原料,经苯磺酰氯磺酰化,在二甲基甲酰胺溶剂中用4-二甲氨基吡啶作为催化剂消除苯磺酸,合成了5a-雄甾-2-烯-17-酮,考察反应温度、反应时间、溶剂和催化剂用量等因素对反应的影响。结果表明,表雄酮苯磺酸酯的合成最佳反应时间为30 h,脱苯磺酸合成5a-雄甾-2-烯-17-酮的最佳反应条件为:反应温度70℃,反应时间60 min,溶剂用量7.5 mL,催化剂4-二甲氨基吡啶用量0.3 g。在此条件下,5a-雄甾-2-烯-17-酮总收率达92.0%。     

Die Autoxidation von Sitosterin III Sitosterylstearat

Autoxidation of Sitosterol III: Sitosterylstearate Sitosterylstearate was oxidized in a stream of oxygen for one hour at 150°C. The oxidation products were separated by thin-layer chromatography and identified. In contrast to oxidation of free sitosterol under identical conditions which yielded oxidation products, in which the 3β-hydroxy group was oxidized to a keto group and the Δ5 double bond was displaced to Δ4, none of these products were formed by the oxidation of β-sitosteryl ester. Moreover, the formation of 6-hydroperoxide, an important primary product of oxidation of the free sterol, was not observed. However, large amounts of the 5,6-epoxide are formed, also with additional oxidation in the 7-position.     

Shifting of the double bond in methyl oleate during hydrogenation

Summary The displacement of the double bond of methyl oleate during hydrogenation with a nickel-kieselguhr catalyst at 180°C. was investigated, particularly with respect to the analysis of dicarboxylic acids, obtained either by oxidation of the reaction products with KMnO₄ in acetic acid or by means of ozone. In the oxidation experiments with KMnO₄ a considerable degradation of lower molecular dicarboxylic acids occurs that makes a quantitative analysis of the isomerization phenomena uncertain. According to the ozonization experiments an equal migration of the double bond in both directions, toward and opposite the ester group, takes place.     

烯基琥珀酸酐(ASA)双键异构体结构的解析研究

针对目前通过ene反应制备烯基琥珀酸酐(ASA)所遇到的双键迁移后位置不确定的问题,利用油酸作原料合成并分离了烯基琥珀酸酐(ASA)-甲酯中含量最多的两个异构体化合物,之后采用臭氧化的方法对其中一个异构体的双键进行切断,并使用了核磁共振、质谱对产物结构进行了表征,从而逆推出了烯基琥珀酸酐(ASA)-甲酯中一个主要异构体的结构,为ASA的深度研究提供了结构上的有力支持。     

Oxidative stability of wax esters by thermogravimetric analysis

Relative oxidative stabilities of sperm whale oil and eight wax ester preparations were determined by comparing oxygen uptake profiles that had been corrected for ester volatility. Wax esters with unsaturation near the ester bond, even though more volatile, are as stable toward oxidation as those with double bonds near the center of each aliphatic chain.     

Identifizierung der Sterine in verschiedenen Lipidgemischen von Schweinen

Identification of Sterols in Various Mixtures of Lipids of Swines The sterol composition of lipid mixtures of blood serum, adrenals, intestinal fat, and back fat of swines was studied. The main sterol is cholesterol, which constitutes 97-99% of the mixture. The remaining sterols, which occur in amounts less than 0.1%, were identified by thin-layer chromatography and gas chromatography on 4 different columns of varying polarity. These are mainly intermediates in the biosynthesis of cholesterol, namely, Δ7-cholestenol, desmosterol, 4-methylchole-sterol, 4-methyl-Δ8(9)-cholestenol, 4,4-dimethylcholesterol, 4,4-dimethyl-Δ8(9)-cholestenol, lanosterol, and dihydrolanosterol. A further sterol with a Δ5,7 double bond, presumably Δ5,7-cholestadien-3β-ol, was recognized from its characteristic UV-absorption. Cholestanol was also present in all samples. Plant sterols could not be detected in the sterol mixtures. Oxidation products of cholesterol, such as Δ4-cholesten-3-on, 7-hydroxy-cholesterol, 7-ketocholesterol, and Δ3,5-cholestadien-7-on were identified. Δ4-Cholesten-3-on is probably formed in vivo, while the others are formed by oxidation of cholesterol during isolation of the sterols.     

Oxidized rapeseed oil methyl ester as a bitumen flux: Structural changes in the ester during catalytic oxidation

Structural changes occurring in the rapeseed oil methyl ester upon catalytic oxidation at 200 °C were examined. Oxidative decomposition of fatty acid chains to lower molecular weight compounds and the formation of oligomers were the major oxidation pathways at 200 °C. FT-IR and ¹H NMR examinations, as well as the fall in iodine number, revealed the disappearance of double bonds. Quantitative analysis of the rapeseed oil methyl ester and the liquid products of its oxidation showed that oxidation of fatty acid methyl esters possessing three and two double bonds was practically complete whereas for structures possessing one double bond the loss of unsaturation amounted to 25% only. The decrease in iodine number from about 110 to about 65 and the 1.5-fold increase in molecular weight of the liquid products in the course of 25-h oxidation suggest that only a part of the unsaturated bonds in the fatty acid methyl ester was engaged in the formation of liquid oligomers and volatile oxidation products. The addition of dicumyl peroxide promoted the formation of organic peroxides during the initial stage of oxidation, which resulted in a higher molecular weight of the liquid products. The volatile oxidation products were found to contain lower molecular weight aldehydes, ketones, free fatty acids and their methyl esters, alkylfurans, lactones, n- and isoalkanes. The reaction schemes for their formation were presented. The results of the study are of importance to the optimization of the conditions for oxidation of the ester in order to obtain a quality ecological bitumen flux.     

Polymorphism in single-acid triglycerides of positional and geometric isomers of octadecenoic acid

The polymorphism of 25 glycerol trioctadecenoates with double bonds ranging from Δ4-Δ17 was investigated by differential scanning calorimetry. Triglycerides withcis bonds in odd positions Δ7-Δ13 exhibited three intermediate melting (β′-) forms, but those withcis bonds in even positions, exceptcis Δ4, lacked β′-forms. Among thetrans compounds, only Δ11, 13, and 14 showed β′-forms. Thecis andtrans Δ5 triglycerides were unusual, because they readily assumed low melting (α-) forms that were not easily converted to high melting (β-) forms. β-Form mp of compounds in each series (cis ortrans) alternated depending upon double bond position; an even position correlated with high mp. Heats of fusion (ΔH_f) for β-forms, likewise, fluctuated with double bond position but nonuniformly;trans Δ6 had the highest ΔH_f (43 cal/g),cis Δ12 the lowest (21 cal/g).     

Oxidation of sulfides to sulfoxides with H2O2/HNO3 reagent system

Selective oxidation of sulfides to sulfoxides is achieved by H₂O₂ using HNO₃ as the promotor. Aromatic and aliphatic sulfides are oxidized to sulfoxides in excellent yields and short reaction times. Different functional groups including C–C double bond, ester, ketone, acetal, alcohol, and oxime groups are tolerated under this reaction condition.     

抗氧剂DLTP生产新工艺

在国外,硫酯类抗氧剂和亚磷酸酯类抗氧剂的消费量之比为1:2.0~3.7,国内约为1:4~5。国外DLTP等硫酯类抗氧剂占有较大的市场份额是与其生产工艺不断改进有关的。抗氧剂DLTP有四种生产工艺,分别是β-氯丙酰氯工艺、丙烯腈工艺、丙烯酸工艺和丙烯酸酯工艺。北京加成助剂研究所开发了酯交换法新工艺,该生产工艺只需两步化学反应、流程短、原料少、三废污染少,产品质量好,抗热氧化能力和抗铜害老化性能高。     

Identification of 3, 6, 9, 12, 15-octadecapentaenoic acid in laboratory-cultured photosynthetic dinoflagellates

Polar and nonpolar chromatograms of fatty acid methyl esters derived from 11 species of photosynthetic, marine dinoflagellates cultured in modified Erd-Schrieber medium contained a component (4-23%) not identifiable by conventional graphic or arithmetic methods. Hydrogenation followed by gas liquid chromatography of the product showed the unknown component to be a straight chained 18 carbon fatty acid methyl ester. Chemical (ch4) ionization mass spectrometry of the isolated ester gave a spectrum characteristic of methyl esters and a mol wt of 288, indicating an 18 carbon molecule with 5 double bonds, or equivalent unsaturation. The IR spectrum showed that the double bonds are nonconjugated, and all are cis in geometry. Electron impact mass spectrometry of the pyrorolidide derivative provided evidence that double bonds are located in the 3, 9, 15 positions and probably also in the 6 and 12 positions of the molecule. these double bond positions were confirmed by NMR spectrometry. Data obtained by quantitation of the algal methyl esters suggest the possibility that these dinoflagellates synthesize 18:5omega3 (shorthand notation for chain length: number of double bond counted from the terminal methyl group) by a 2 carbon chain shortening of 20:5omega3, rather than by the insertion of a delta3 bond into 18:4omega3.