Synthesis of glycosylated-β(1-4)-amino(methoxy) and -oxyamino carbohydrate analogues
作者:Olivier Renaudet、Pascal Dumy
DOI:10.1016/s0040-4020(02)00079-0
日期:2002.3
The synthesis of new oligosaccharides containing nitrogen or oxygen–nitrogen in interglycosidic linkage is described. Several modified β-N- and β-O-N linked disaccharides with glucose or galactose as reducing unit such as lactose or cellobiose analogues have been prepared stereoselectively using two different methods. All these compounds were fully characterised by one and two dimensional NMR studies
描述了糖苷间键合中含有氮或氧-氮的新低聚糖的合成。已经使用两种不同方法立体选择性地制备了几种以葡萄糖或半乳糖为还原单元的修饰的β- N-和β- O - N连接的二糖,例如乳糖或纤维二糖类似物。通过一维和二维NMR研究,质谱法对所有这些化合物进行了充分表征,获得了Gal-β- N-(1,4)-Gal衍生物10的晶体结构。这些类型的寡糖结构修饰可用于研究各种生化过程。
Investigation of the Moffatt−Swern Oxidation in a Continuous Flow Microreactor System
作者:Jacobus J. M. van der Linden、Peter W. Hilberink、Claudia M. P. Kronenburg、Gerardus J. Kemperman
DOI:10.1021/op700228e
日期:2008.9.19
The Moffatt-Swern oxidation of different alcohols is performed in a continuous flow microreactor system. The microreactor process offers significant advantages over the batch process. First, because of the small reactor volume, accumulation of the labile trifluoroacetoxydimethylsulfonium salt (3) and alkoxydimethyl-sulfonium salt (5) is minimized. Second, because of the short residence times, which can be applied in the microreactor, the exothermic Pummerer rearrangement of the unstable intermediate 3 is limited. Because of this, the process can be operated at remarkably high temperatures in comparison with a batch reaction, viz. 0-20 degrees C instead of -70 degrees C. In the present study, a continuous flow microreactor system was optimized using reactors of different volumes allowing modulation of the residence times of labile intermediates. The efficiency of mixing was studied using different mixing devices. It has been shown that the continuous How microreactor is an ideal tool for rapid optimization of reaction parameters. Furthermore, the scaleability and reliability of the microreactor was tested by running the system for several hours. For testosterone, the system was in process for 1.5 h without any problems, resulting in an 4-androstene-3,17-dione production rate of 64 g center dot h(-1).
TRONCHET, JEAN M. J.;BIZZOZERO, NICOLETTA;GEOFFROY, MICHEL, CARBOHYDR. RES., 191,(1989) N, C. 138-143
作者:TRONCHET, JEAN M. J.、BIZZOZERO, NICOLETTA、GEOFFROY, MICHEL