semisynthesis and total synthesis of vinca alkaloids

... addition of 50 mL of 10% citric acid, the mixture was extracted three times with 30 mL of EtOAc The combined organic layers were washed twice with 20 mL of 10% citric acid, 20 mL of water and 20 mL of ... addition of mL of water and slowly warmed to 23 °C over 1.5 h The reaction mixture was extracted three times with 10 mL of DCM The combined organic layers were washed with 10 mL of 5% NaHCO3, water and ... 4-43 OH and LiOH (1.0 mg, 0.021 mmol) were dissolved in mL O of a mixture of EtOH and water (2/1) under an inert atmosphere of argon The reaction mixture was stirred for 18 h at 23 °C and poured...

Ngày tải lên: 10/09/2015, 15:48

Ngày tải lên: 10/09/2015, 15:49

Ngày tải lên: 10/09/2015, 15:50

Ngày tải lên: 10/09/2015, 15:50

... University of Singapore, Singapore 2007 - 2011 Medicinal Chemistry Programme (PhD student under the supervision of Dr Martin Lear) • Affinity-Guided Isolation, Structure Elucidation and Total Synthesis ... mathematics and economic laws University of Applied Sciences, Isny/Allgaeu, Germany 1997 - 2001 Graduate of Pharmaceutical Chemistry (“Diplom-Ing.”) • Awarded patent for thesis work on the synthesis of ... Roche Diagnostics Department of Rare Reagents Hoechst AG, Frankfurt, Germany 1992 - 1995 Today part of the Sanofi-Aventis group Chemical Technician Apprenticeship and Qualification • Completed...

Ngày tải lên: 10/09/2015, 15:50

... cleavage of PMB 86 Scheme 6.7: Synthesis of azido tripeptide and Staudinger reaction 86 Scheme 6.8: Final coupling and synthesis of trimethyl ester of target peptide 87 Scheme 6.9: Conversion of the ... ASSIGNMENT AND TOTAL SYNTHESIS OF AN ANTIMALARIAL LIPOPEPTIDE SHIBAJI KUMAR GHOSH (M.Sc, UNIVERSITY OF CALCUTTA) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF CHEMISTRY ... been synthesised and their absolute configuration assigned to the chiral centres with the help of Marfey’s reagent The full structure of N1708 has been confirmed by the total synthesis of the...

Ngày tải lên: 10/09/2015, 15:52

... PART I TOTAL SYNTHESIS AND BIOLOGICAL EVALUATION OF ANTILLATOXIN AND FRAGMENTS PART II SYNTHETIC STUDIES TOWARDS THE TOTAL SYNTHESIS OF CYTOCHALASANS AND TUBEROSTEMONINE APPENDIX ... Chapter : Total Synthesis of Antillatoxin 1.4.4 Synthesis of Fragment 34 Using Indium-Mediated Allylation 1.4.4.1 Synthesis of Fragment 65 - Strategy With aldehdye 41 and two allylic bromides 42 and ... stereochemistries of C4 and C5 In our group, we have been working on the synthesis of the isomers of C4 and C5 as NOE studies of large rings is known to be unreliable.9 Later, the NMR data of the synthetic...

Ngày tải lên: 16/09/2015, 08:31

... Material (ESM) In spite of intensive research into one-dimensional structures of metal oxides in particular and NWs in general, our understanding of the mechanisms of their formation and growth is still ... accumulated in the Fe3O4 and FeO layers and cannot directly affect the 377 Nano Res (2009) 2: 373 379 growth of the NWs Figure shows our understanding of the NW formation conditions and a suggested mechanism ... basis of our experimental results and literature data The formation of NWs occurs when three layers of iron oxides are gradually formed by oxidation of iron We believe that the growth of NWs...

Ngày tải lên: 20/03/2014, 13:07

... homooligomerization of NP, formation of NP-induced intracellular inclusions, interaction of NP with VP35 and for the function of NP in RNA synthesis Materials and methods Cells and cDNA transfections ... NP and VP35 (binding is enhanced in the absence of C2) and is essential for the function of NP in transcription and replication of MARV RNA It is possible that the conformational flexibility of ... down by glutathione-sepharose and the amount of coprecipitated NP and mutants of NP was quantified to assess the interaction of VP35 with the coiled coils (Figs 3B and 3C) While NP was readily...

Ngày tải lên: 18/06/2014, 18:20

... homooligomerization of NP, formation of NP-induced intracellular inclusions, interaction of NP with VP35 and for the function of NP in RNA synthesis Materials and methods Cells and cDNA transfections ... NP and VP35 (binding is enhanced in the absence of C2) and is essential for the function of NP in transcription and replication of MARV RNA It is possible that the conformational flexibility of ... down by glutathione-sepharose and the amount of coprecipitated NP and mutants of NP was quantified to assess the interaction of VP35 with the coiled coils (Figs 3B and 3C) While NP was readily...

Ngày tải lên: 20/06/2014, 01:20

... choice of G This completes the proof of Claim 3.1 In view of Claim 3.1 and Lemma 3.1, B must be K4 -minor-free By the proof of (Note that Claims 2.1– Claim 2.1, B ∼ K2 , so that B is 2-connected and ... including the colour of z0 , and each other vertex and edge of B has a list of at least colours By Lemma 3.2 this colouring can be extended to all the remaining vertices and edges of B This shows ... with z0 is given a list of three colours not including the colour of z0 , and every other vertex and edge of K4 is given a list of five colours, then the given colouring of z0 can be extended to...

Ngày tải lên: 07/08/2014, 13:21

... in situ effect of licofelone on the gene expression and protein synthesis of the major collagenolytic enzymes (MMP-13 and cathepsin K) and aggrecandegrading proteases (ADAMTS-4 and ADAMTS-5) in ... score of 5.1 (3–11) and a safraninO score of (0–4) Specimens from licofelone-treated groups had a Mankin score of 3.5 (0–10) and a safranin-O score of 0.4 (0–3) with the 2.5 mg dosage and a Mankin ... resorption of the calcified cartilage and subchondral bone in the early phase of the disease [18] Licofelone treatment was shown to reduce the level of synthesis of cathepsin K in both of these...

Ngày tải lên: 09/08/2014, 06:23

Ngày tải lên: 14/11/2014, 09:37

Ngày tải lên: 10/04/2015, 17:11

... least one boundary is of Type (b) and none of the boundaries is of Type (c) 3.4 Case 3.3: At least one boundary is of Type (c) and none of the boundaries is of Type (b) ... University of Singapore Finally, my special thanks go to my wife Yang Jing for her support, patience and understanding, and to my parents and grandparents for their love, support, and encouragement ... one boundary is of Type (c) and none of the boundaries is of Type (b) 4.4 80 Case 4.4: At least one boundary is of Type (b) and at least one boundary is of Type (c) ...

Ngày tải lên: 09/09/2015, 11:27

... TANDEM ISOMERIZATION REACTION OF ALKYNES: TOTAL SYNTHESIS OF ALPHA-YOHIMBINE FENGWEI 2012 TANDEM ISOMERIZATION REACTIONS OF ALKYNES: TOTAL SYNTHESIS OF ALPHA-YOHIMBINE FENG ... isomerization of alkynes to allenes Scheme 3.1.1 Total synthesis of alpha- yohimbine, route1 Scheme 3.1.2 Total synthesis of alpha- yohimbine, route Scheme 3.1.3 Total synthesis of alpha- yohimbine, ... Euryfuran synthesis via IMDAreaction of alkoxyallene Scheme 1.3.9 Total synthesis of Forskoin via intramolecular Diels-Alder reaction of allenyl ether Scheme 1.3.10 Total synthesis of tirkentrins...

Ngày tải lên: 09/09/2015, 17:56

... high-yielding synthesis of the aromatic unit (1-151) of 284 platensimycin Scheme 5.9 Preparation of the C6-methoxy analog (5-60) of (-)- 286 platensimycin Scheme 5.10 Completion of the total synthesis of ... product 4-60 (A) and its proposed mechanism of formation (B) Scheme 4.13 Synthesis of the Bn-protected homoallyl acid 4-62 172 Scheme 4.14 Synthesis of an inseparable mixture of cis-/trans- 175 ... approach Scheme 5.2 Synthesis of (-)-dienone 4-1 via the tosyl lactol 5-3 246 Scheme 5.3 Synthesis of (-)-dienone 4-1 via the bromo lactol 5-11 250 Scheme 5.4 Synthesis of the TFA salts of amino acid...

Ngày tải lên: 10/09/2015, 08:39

... Lewis acid and adjustment of the protecting groups to achieve the total synthesis of bielschowskysin   ix   LIST OF FIGURES AND SCHEMES Chapter 1: Bielschowskysin: A Structurally and Biologically ... Sulikowski’s synthesis of the tetracyclic core of bielschowskysin 15 Scheme 1.17 Paquette’s synthesis of dihydropseudopterolide and gorgiacerone 17 Scheme 1.18 Paquette’s synthesis of acersolide ... Figure 1.8 : Macrocyclisation and allene formation 31 Figure 1.9: Retrosynthesis of left and right fragment 32 Scheme1.1 Proposed biosynthesis of bielschowskyane skeleton and related cembranes Scheme...

Ngày tải lên: 11/09/2015, 09:13

... moiety in the total synthesis of kallolide A16 and rubifolide17 Other methods include selenoxide elimination18,19,20 of butyrolactone 49, Wittig reaction21, alkylation of silyloxy furan22 and ring ... furanocembranoid synthesis of the natural product acersolide 92 in 1993 (Scheme 1.18) 16 Scheme 1.17 Paquette’s synthesis of dihydropseudopterolide and gorgiacerone17 17 Scheme 1.18 Paquette’s synthesis of ... catalysed deprotection of TES and TBS groups Benzyl protection of diol 214 using sodium hydride and benzyl bromide in DMF under standard conditions, and acetonide deprotection of dibenzyl compound...

Ngày tải lên: 11/09/2015, 09:13

Ngày tải lên: 11/09/2015, 09:13