排序方式: 共有14条查询结果,搜索用时 31 毫秒
1.
Cesare Accinelli Anna Barra Caracciolo Paola Grenni 《International journal of environmental analytical chemistry》2013,93(8):579-587
Numerous studies have documented that a wide number of pharmaceuticals used in human and veterinary medicine have the potential to enter the aquatic ecosystem. The antiviral prodrug oseltamivir phosphate has received recent attention with regard to its possible use against the highly pathogenic H5N1 virus. This preliminary laboratory study investigated the persistence of the active antiviral drug, oseltamivir carboxylate (OSC), in water samples taken from an irrigation canal. After an initial rapid decrease, OSC concentrations slowly decreased during the remaining incubation period. Approximately 65% of the initial OSC amount remained in water at the end of the 36-day incubation period. A small amount of OSC was lost both from sterilized water and from sterilized water/sediment samples, suggesting a significant role for microbial degradation. Stimulating microbial processes by the addition of sediments resulted in reduced OSC persistence. Presence of OSC (1.5?µg?mL?1) did not significantly affect the metabolic potential of the water microbial population, estimated by glyphosate and metolachlor mineralization. In contrast, OSC caused an initial transient decrease in the size of the indigenous microbial population of water samples. 相似文献
2.
The key steps in the enantioselective synthesis of Tamiflu include an asymmetric Diels-Alder reaction, Mitsunobu inversion using Fukuyama modified Weinreb reagent, carbamate directed epoxidation. Epoxide opening with trimethylsilyl azide furnished a 3:1 mixture of regioisomers that converged to afford the same aziridine. Attempted preparation of the unsaturated ester regioselectively using 2-iodoxybenzoic acid (IBX) following Nicolaou’s protocol failed. The unsaturated ester was prepared by phenylselenylation followed by selenoxide elimination. 相似文献
3.
Our third generation synthesis of Tamiflu was achieved in 12 steps from commercially available starting materials, using the Diels-Alder reaction and Curtius rearrangement as key steps. 相似文献
4.
5.
We report a full account of our work towards the development of an eight‐step synthesis of anti‐influenza drug (?)‐oseltamivir (Tamiflu) from commercially available starting materials. The final synthetic route proceeds with an overall yield of 30 %. Key transformations include a novel palladium‐catalyzed asymmetric allylic alkylation reaction (Pd‐AAA) as well as a rhodium‐catalyzed chemo‐, regio‐, and stereoselective aziridination reaction. 相似文献
6.
Dr. Hayato Ishikawa Takaki Suzuki Dr. Hideo Orita Dr. Tadafumi Uchimaru Prof. Dr. Yujiro Hayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(42):12616-12626
The efficient asymmetric total synthesis of (?)‐oseltamivir, an antiviral reagent, has been accomplished by using two “one‐pot” reaction sequences, with excellent overall yield (60 %) and only one required purification by column chromatography. The first one‐pot reaction sequence consists of a diphenylprolinol silyl ether mediated asymmetric Michael reaction, a domino Michael reaction/Horner–Wadsworth–Emmons reaction combined with retro‐aldol/Horner–Wadsworth–Emmons reaction and retro Michael reactions, a thiol Michael reaction, and a base‐catalyzed isomerization. Six reactions can be successfully conducted in the second one‐pot reaction sequence; these are deprotection of a tert‐butyl ester and its conversion into an acyl chloride then an acyl azide, Curtius rearrangement, amide formation, reduction of a nitro group into an amine, and a retro Michael reaction of a thiol moiety. A column‐free synthesis of (?)‐oseltamivir has also been established. 相似文献
7.
8.
Hiroshi OsatoIan L. Jones Huini GohChristina L.L. Chai Anqi Chen 《Tetrahedron letters》2011,52(48):6352-6354
A three-step, one-pot process has been developed for the synthesis of 5-epi-shikimic acid derivative 5 using inexpensive and abundant d-ribose as the starting material. Based on this pivotal intermediate, the syntheses of two key shikimic acid derivatives 6 and 7 for Tamiflu have been achieved in a concise and practical fashion. 相似文献
9.
Subhash P. Chavan Appasaheb L. Kadam Shrikrishna S. Shinde Rajesh G. Gonnade 《化学:亚洲杂志》2020,15(3):415-424
A unified synthetic strategy for oseltamivir phosphate (tamiflu), (S)‐pipecolic acid, and its 3‐hydroxy derivatives from furan derived common chiral bicycloaziridino lactone synthon is described here. Key features are the short (4‐steps), enantiopure, and decagram‐scale synthesis of common chiral synthon from furan and its first‐ever application in the total synthesis of biologically active compounds by taking the advantages of high functionalization ability of chiral synthon. 相似文献
10.
A very efficient two‐step synthesis was developed to prepare the key intermediate in Corey's Tamiflu synthesis. DBU (1,8‐diazabicyclo[5.4.0] undec‐7‐ene) was used as a multifunctional catalyst for a series of reactions in a one pot procedure. The new synthesis was featured by the good availability of the starting material and the ease of the synthetic steps. This method might be practical for large scale preparations. 相似文献