（＋）二氢香芹酮氰醇的合成

利用手性元途径来合成光学活性化合物近年来受到特别重视。在利用天然易得的糖、氨基酸和萜类化合物来合成各种手性元上,发展了不少十分有价值的策略［１］。（＋）二氢香芹酮分子中有两个手性碳,是一种手性合成常用的原料。我们曾报道了由（＋）二氢香芹酮合成（＋）１...     

L-苏式二氢鞘氨醇的立体选择性合成

二氢鞘氨醇（ＤＨＳ）是２－氨基－１，３－二羟基的饱和长链氨基醇化合物，是构成鞘脂类（包括鞘磷脂和糖鞘脂）的主链部分．由于鞘脂类在自然界中来源稀少，又很难得到纯品．因此，作为鞘脂类主链部分的二氢鞘氨醇的合成有重要的意义［１］．二氢鞘氨醇有两个手性碳，共...     

从D-甘露糖醇合成(2S, 3R)-鞘氨醇

以D-甘露糖醇为原料, 在制得了(2E)-4, 5-氧异亚丙基戊烯酸酯(5)以后,经不对称双羟基化反应、环硫酸酯化和叠氮化钠区域选择性开环等12步反应以7.7%的总产率合成了标题化合物的2, 3-二苯甲酰产物, 由此为鞘氨醇和神经鞘脂类化合物的合成开辟了又一新的途径。     

Cu-Co尖晶石催化CO_2加氢合成低碳醇(Ⅰ)(英文)

制备了几种CU－CO尖晶石,并用于催化CO2加氢合成低碳醇反应。结果表明,Cu－Co尖晶石是一种极具潜力的催化剂前驱体,具有出色的C2＋醇合成能力。但是,当在该催化剂中加入KOH时,这种能力下降。XRD表征表明,KOH的加入破坏了CU－Co合金的生成。一些结果被讨论。     

复合床层中合成低碳醇的研究(英文)

研究了复合催化剂床对合成低碳醇反应行为的影响。结果表明,采用复合床可以提高反应产物中低碳醇的选择性。第一段催化床层的反应产物的分布和第二段催化床层的反应条件直接影响最终的反应结果。第一段催化剂床层中ＣＯ的转化率或甲醇的选择性过高都不利于提高反应产物中低碳醇的选择性。     

类水滑石催化合成聚(碳酸1,4-丁二醇)酯二醇

采用共沉淀法制备了镁铝类水滑石(Mg-Al-CO3LDH)、镁锌铝类水滑石(Mg-Zn-Al-CO3LDH)和锌铝类水滑石(Zn-Al-CO3LDH),并研究了它们在碳酸二苯酯(DPC)与1,4-丁二醇(1,4-BD)酯交换合成聚碳酸酯二醇(PCDL)反应中的催化活性。在常压反应阶段,以苯酚的产率表征催化剂的活性;在减压缩聚阶段,以产品的数均分子量Mn和羟基值来表征催化剂的活性。结果发现,Zn-Al LDH具有良好的催化活性。在优化反应条件下,获得了Mn和羟基值分别为1600和70.8mg KOH/g的PCDL。     

二碘化钐促进的 β-碲代酯(腈)的合成

本文报道在室温, 中性介质中研究二碘化钐在合成中的应用. 在二碘化钐作用下,二碲醚发生Te-Te键还原断裂, 生成碲负离子物种, 后者再与α,β-不饱和酯(腈)发生Michael加成, 得到β-碲代酯(腈), 产率较高.     

2,3-二溴-4,5-二羟基苄醇的合成

以香兰素为起始原料,经溴代,还原,脱甲基合成了具有生物活性的天然产物--2,3-二溴-4,5-二羟基苄醇,总收率14%,其结构经1H NMR,IR和元素分析表征.     

meso-四苯基-2,3-二氢卟啉-2,3-二醇的合成

研究了一种关于meso-四苯基-2,3-二氢卟啉-2,3-二醇的避免使用昂贵且剧毒的四氧化锇的合成方法,整个合成过程中所用试剂廉价易得,反应操作简单.该合成方法可同时得到顺、反两种目标产物异构体.     

(E)-烯基甲苯基硅醇的合成

从烯丙基甲苯基氨基硅烷出发,经过基化反应,得到(E)-烯基氨基硅烷, 然后水解成(E)-烯基硅醇。研究了烯丙基氨硅烷碳负离子烷基化学反应的区域选择性,建立了去除α-异构体的方法。     

Uncatalyzed synthesis of new substituted dihydro-2H-dipyrimido[1,2-a,4,5-d]pyrimidine-2,4(3H)-dione

Research on Chemical Intermediates - A convenient and new method has been developed for the synthesis of highly substituted dihydro-2H-dipyrimido[1,2-a,4,5-d]pyrimidine-2,4(3H)-dione derivatives by...     

Synthese de dihydro-6,7 benzo-b [1H] azonines par extension de cycle de dihydro-4,5 benzo-b [1H] azepines

Activated acetylnic reagents add to heterocyclic enamines 4,5-dihydro-1H-benzo[b]azepines and by electrocyclisation, give 6,7-dihydro-1H-benzo[b]azoninines. The structure of those new heterocycles is demonstrated by mass spectra, ¹H and ¹³C nmr.     

Chemomicrobial synthesis of (R)- and (S)-lavandulol

(R)- and (S)-Lavandulol are important compounds in the cosmetics industry and in pheromone research. We have developed syntheses of (R)- and (S)-lavandulol from (S)- and (R)-limonene, respectively, by microbial Baeyer-Villiger oxidation of the intermediate unsaturated hydroxy ketone. It has been found that the same strain of Acremonium roseum can be successfully used in the key step of the synthesis of both enantiomers of lavandulol.     

PEG-400 as an efficient and recyclable reaction medium for the synthesis of 2-aryl-2-methyl-4,5-diphenyl-2,3- dihydro-2H-imidazoles

A productive natural method has been produced for the synthesis of 2-aryl-2-methyl-4,5-diphenyl-2,3-dihydro-2H-imidazoles in great yields under catalyst free-conditions utilizing polyethylene glycol (PEG-400) as a green reaction medium. The highlights of this new method are shorter reaction times, good yields, room temperature, and use of nontoxic, inexpensive, and recyclable PEG-400.     

Pyrimidines. XIX. Pyrimido[4,5-e]dihydro-1,3-oxazines and related compounds

A number of 2-substituted 4,5-dihydroxy-6-(substituted aminomethyl)pyrimidines (VIII) were prepared from the corresponding 2-substituted 4,5-dihydroxypyrimidines (VII) by a new pyrimidine Mannich reaction. The structure of VIII was proved by an independent synthesis. Further study of this reaction led to the synthesis of a new class of compounds: the pyrimido[4,5-e]dihydro-1,3-oxazines (VI).     

A condensed synthesis of dihydro-3(2H)-furanone

A straight forward synthesis of dihydro-3(2h)-furanone is described. An attempted preparation of the oxetan-3-one precursor 10 by this method gave, instead, the ring enlargement product 11.     

An efficient synthesis of dihydro- and tetrahydropyrans via oxonium-ene cyclization reaction

An efficient method has been developed for the synthesis of 2,3-dihydropyrans and 4-methylenetetrahydropyrans from aldehydes and substituted homoallyl alcohols in benzene mediated by boron trifluoride etherate in good yields. The reaction proceeds via oxonium-ene reaction.     

Ring expansion reactions of 1,3-dithiolans and 1,3-dithians. A new synthesis of dihydro-1,4-dithiins and dihydro-1,4-dithiepins

A mild and convenient method for ring expansion of 1,3-dithiolans and 1,3-dithians to dihydro-1,4-dithiins and dihydro-1,4-dithiepins, respectively, using phenyl selenenyl chloride in methylene chloride is described. A mechanism involving sulphenyl chloride derivatives as intermediates is proposed.