- A new scalable synthesis of entecavir
-
A new synthesis of entecavir from D-glucose in an average total yield of 3.5% was achieved via an intramolecular nitrile oxide cycloaddition (INOC) reaction and a Peterson olefination as key-steps. The present process was designed for industrial application, using widely available raw materials, simple and cheap reagents and avoiding low reaction temperatures, which are very common in the synthetic approaches towards similarly complex structures.
- Gioti, Efthymia G.,Koftis, Theocharis V.,Neokosmidis, Efstratios,Vastardi, Elli,Kotoulas, Stefanos S.,Trakossas, Sakellarios,Tsatsas, Theodoros,Anagnostaki, Elizabeth E.,Panagiotidis, Theodoros D.,Zacharis, Constantinos,Tolika, Evanthia P.,Varvogli, Anastasia-Aikaterini,Andreou, Thanos,Gallos, John K.
-
supporting information
p. 519 - 527
(2017/12/29)
-
- NOVEL 3-SUBSTITUTED 5-AMINO-6H-THIAZOLO[4,5-D]PYRIMIDINE-2,7-DIONE COMPOUNDS FOR THE TREATMENT AND PROPHYLAXIS OF VIRUS INFECTION
-
The present invention relates to compounds of formula (I), wherein R1, R2 and R3 are as described herein, and their prodrugs or pharmaceutically acceptable salt, enantiomer or diastereomer thereof, and compositions including the compounds and methods of using the compounds.
- -
-
Paragraph 0237; 0238; 0239
(2016/08/07)
-
- Synthesis of modified Trichinella spiralis disaccharide epitopes and a comparison of their recognition by chemical mapping and saturation transfer difference NMR
-
A rat monoclonal antibody 9D4 raised against the cell surface N-glycan of the parasite Trichinella spirallis protects rats against further infection. The terminal disaccharide β-d-Tyvp(1→3)β-d-GalNAcp (2) represents the immunodominant portion of the antig
- Cui, Lina,Ling, Chang-Chun,Sadowska, Joanna,Bundle, David R.
-
-
- Asymmetric three-component domino reaction: An original access to chiral nonracemic 1,3-thiazin-2-ones
-
A new asymmetric three-component domino process, based on a diastereoselective hetero-Diels-Alder reaction, involving an aldehyde, an alkene, and a chiral thiocarbamate was developed. The chiral auxiliary is directly removed during this process, leading to enantioenriched 2H-1,3-thiazin-2-ones with up to 96% ee.
- Peudru, Flavie,Le Cavelier, Fabien,Lohier, Jean-Francois,Gulea, Mihaela,Reboul, Vincent
-
supporting information
p. 5710 - 5713
(2013/12/04)
-
- Synthesis of (2S,4S)-4-hydroxyproline from D-glucose
-
Diacetone-D-glucose 1 gives 3-O-methylxanthate 2 on reaction with NaH=Me I. Reductive deoxygenation of compound 2 by Bu3SnH gives the corresponding 3-deoxy glucose derivative 3 and on acid-catalyzed regioselective deprotection of C-5,6-acetonide gives the diol 4. The diol on oxidative cleavage with NaIO4 gives the aldehyde 5, which on further condensation with benzylamine followed by reduction with NaBH4 gives the amine 7. Z-Protection of the amine followed by methanolysis gives methyl furanoside 9. Reaction of 9 with methanesulfonyl chloride=Et3N gives the corresponding C-3-O-mesylate derivative 10. Catalytic hydrogenation of compound 10 (Pd=C=H2=MeOH 3 kg) gives bicyclic oxaazo compound 11, due to deprotection of the N-benzyl- and Z-protecting groups and intramolecular nucleophilic displacement of the C-2-O-mesylate by the C-5 amine in a one-pot reaction. Z-Protection of the amine 11 followed by acid-catalyzed hydrolysis gives acetal 13. Reduction of acetal by use of NaBH4 gives Z-prolinol 14. Selective oxidation of diol 14 by (2,2,6,6-tetramethylpiperidin-1-yl)-oxyl (TEMPO)=[(bis)(acetoxy)iodo]-benzene (BAIB) and NaClO2=NaH 2PO4, followed by Z-deprotection, gives the title compound I in 3.5% overall yield from D-glucose. Copyright Taylor & Francis Group, LLC.
- Mereyala, Hari Babu,Pathuri, Gopal,Nagarapu, Lingaiah
-
p. 1278 - 1287
(2012/04/17)
-
- A USEFUL METHOD FOR CONVERTING 2 ALCOHOLS TO THEIR CHLORIDES WITH RETENTION OF CONFIGURATION
-
Xanthate esters of 2 alcohols are converted to their chlorides with retention of configuration in good yield by use of sulfuryl chloride.
- Kozikowski, A. P.,Lee, Jaemoon
-
p. 3053 - 3056
(2007/10/02)
-