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Search for "TBAI" in Full Text gives 50 result(s) in Beilstein Journal of Organic Chemistry.

Bromide-assisted chemoselective Heck reaction of 3-bromoindazoles under high-speed ball-milling conditions: synthesis of axitinib

  • Jingbo Yu,
  • Zikun Hong,
  • Xinjie Yang,
  • Yu Jiang,
  • Zhijiang Jiang and
  • Weike Su

Beilstein J. Org. Chem. 2018, 14, 786–795, doi:10.3762/bjoc.14.66

Graphical Abstract
  • . Currently, the Heck reaction is usually carried out by adding an excess of phase-transfer catalyst such as tetrabutylammonium bromide (TBAB) or tetrabutylammonium iodide (TBAI) to increase the reaction yield under both solvent-heating [19][20][21][22][23] and solvent-free conditions [24][25][26][27
  • , TBAI or tetrabutylammonium chloride (TBAC) did not provide a satisfactory result (Table S1, entries 3 and 4). It was interesting to find that using bromide salts (LiBr, NaBr, KBr and TBAB) as additives, not only the conversion rate of 1a was increased, but also the side-product 4a was suppressed
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Published 06 Apr 2018

One-pot preparation of 4-aryl-3-bromocoumarins from 4-aryl-2-propynoic acids with diaryliodonium salts, TBAB, and Na2S2O8

  • Teppei Sasaki,
  • Katsuhiko Moriyama and
  • Hideo Togo

Beilstein J. Org. Chem. 2018, 14, 345–353, doi:10.3762/bjoc.14.22

Graphical Abstract
  • mixture of 1,2-dichloroethane (DCE) and water at 90 °C was carried out to give 3-bromo-4-phenylcoumarin (3Aa) in 68% yield (Table 2, entry 7). When the iodocyclization of phenyl ester 2Aa with tetrabutylammonium iodide (TBAI, 2.0 equiv)/Na2S2O8 (1.5 equiv) was carried out, the yield of iodocyclization
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Published 05 Feb 2018

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

  • Ranjana Aggarwal and
  • Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

Graphical Abstract
  • in situ intramolecular cyclization of 5-aminopyrazole-4-caroxylate 35 with β-haloaldehydes 36 via the corresponding imine derivative was carried out in presence of Pd(PPh3)2Cl2 (1.0 mol %), Cu2O (1.0 mol %), 1,10-phenanthroline (2.0 mol %), TBAI (6 mol %), by Batra et al. [50] to generate the
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Published 25 Jan 2018

CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na

  • Hélène Guyon,
  • Hélène Chachignon and
  • Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

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Published 19 Dec 2017

Synthesis of ergostane-type brassinosteroids with modifications in ring A

  • Vladimir N. Zhabinskii,
  • Darya A. Osiyuk,
  • Yuri V. Ermolovich,
  • Natalia M. Chaschina,
  • Tatsiana S. Dalidovich,
  • Miroslav Strnad and
  • Vladimir A. Khripach

Beilstein J. Org. Chem. 2017, 13, 2326–2331, doi:10.3762/bjoc.13.229

Graphical Abstract
  • , NaI, DMF, 150 °C (83%); (c) KOH, MeOH, 65 °C (96%). (a) MCPBA, CH2Cl2, 20 °C (90%); (b) NBS, DME, 20 °C; (c) KOH, MeOH, 20 °C (85% over 2 steps). (a) BnBr, DMAP, Bu2SnO, TBAI, DIPEA, 110 °C (94%); (b) PCC, CH2Cl2, 20 °C (84%); (c) H2, Pd/C, 20 °C (99%); (d) NaBH4, EtOH, −25 °C (61%); (e) KOH, MeOH, 65
  • °C (96%). (a) TsCl, DMAP, Py, 30 °C (91%); (b) Py, 115 °C (65%); (c) KOH, MeOH, 20 °C (52%). (a) NaBH4, EtOH, −25 °C (49%); (b) KOH, MeOH, 65 °C (85%). (a) Anisaldehyde, TMSCl, MeOH, 20 °C; (b) BnBr, DMAP, Bu2SnO, TBAI, DIPEA, 110 °C (86% over 2 steps); (c) PCC, CH2Cl2, 20 °C (81%); (d) H2, Pd/C, 20
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Published 02 Nov 2017

Mechanochemical synthesis of small organic molecules

  • Tapas Kumar Achar,
  • Anima Bose and
  • Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

Graphical Abstract
  • . Mal and co-workers reported a metal free, solvent-free and room temperature synthesis of amide bonds at 62–75% yield under ball-milling (21 Hz) from aromatic aldehydes and N-chloramine in presence of 20 mol % of tetrabutylammonium iodide (TBAI) and 2.0 equiv of TBHP (Scheme 16) [79]. Aromatic
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Published 11 Sep 2017

The chemistry and biology of mycolactones

  • Matthias Gehringer and
  • Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

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Published 11 Aug 2017

Transition-metal-catalyzed synthesis of phenols and aryl thiols

  • Yajun Liu,
  • Shasha Liu and
  • Yan Xiao

Beilstein J. Org. Chem. 2017, 13, 589–611, doi:10.3762/bjoc.13.58

Graphical Abstract
  • stoichiometric amount of Cu(OAc)2 in the presence of Ag2CO3 and TBAI as additives in DMF at 100 °C (Scheme 26). Notably, their protocol was so efficient that the reactions could accomplish within 1 hour. The substrate scope showed benzamides bearing both electron-donating groups and electron-withdrawing groups
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Published 23 Mar 2017

Nucleophilic displacement reactions of 5′-derivatised nucleosides in a vibration ball mill

  • Olga Eguaogie,
  • Patrick F. Conlon,
  • Francesco Ravalico,
  • Jamie S. T. Sweet,
  • Thomas B. Elder,
  • Louis P. Conway,
  • Marc E. Lennon,
  • David R. W. Hodgson and
  • Joseph S. Vyle

Beilstein J. Org. Chem. 2017, 13, 87–92, doi:10.3762/bjoc.13.11

Graphical Abstract
  • following addition of NaI (500, 50 or 5 mol %) or TBAI (50 or 5 mol %). Following the successful application of VBM using a thiolate nucleophile, we were prompted to explore related reactions of alkylselenols. However, the sensitivity of such compounds towards aerial oxidation meant that, in our hands, an
  • ) remained untransformed during (dry) VBM or liquid-assisted grinding (LAG) in the presence of DMF with excess KSeCN (3 equiv). As found previously, the addition of catalytic TBAI (vide supra) did not alter this outcome nor did the use of a larger excess (5 equiv) of selenocyanate. The addition of DMF to the
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Published 13 Jan 2017

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

  • Pavel Nagorny and
  • Zhankui Sun

Beilstein J. Org. Chem. 2016, 12, 2834–2848, doi:10.3762/bjoc.12.283

Graphical Abstract
  • atoms covalently bonded to a benzylic carbon (Scheme 8). In 2016 Maruoka and Shirakawa followed up the aforementioned studies by demonstrating that tetraalkylammonium salts L5, L6, L11 and L12 as well as TBAI could activate imines toward aza-Diels–Alder reaction with Danishefsky’s diene (Scheme 9) [51
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Published 23 Dec 2016

Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(−)-myrtenol nitrate

  • Sean P. Bew,
  • Glyn D. Hiatt-Gipson,
  • Graham P. Mills and
  • Claire E. Reeves

Beilstein J. Org. Chem. 2016, 12, 1081–1095, doi:10.3762/bjoc.12.103

Graphical Abstract
  • with bromoacetone was a requirement for an efficient ‘bromide to nitrate’ substitution. Changing tactics we opted to generate the more reactive iodoacetone in situ from chloroacetone (42) and a stoichiometric quantity of tetra-n-butylammonium iodide (TBAI). Gratifyingly the iodoacetone reacted readily
  • further 16 hours, the majority of (E)-60 had reacted as judged by TLC and 1H NMR analysis. Removing the sodium chloride via a simple filtration was more advantageous than the previously employed organic soluble and more expensive TBAI (Scheme 6). Straightforward flash-column purification afforded (E)-10
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Published 27 May 2016

Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners

  • Mohamed Ramadan El Sayed Aly,
  • Hosam Ali Saad and
  • Shams Hashim Abdel-Hafez

Beilstein J. Org. Chem. 2015, 11, 1922–1932, doi:10.3762/bjoc.11.208

Graphical Abstract
  • : (a) Propargyl bromide, NaH, Et2O/DMF (quant. for both 26 and 30); (b) 3, CuSO4·5H2O, L-AsAc, THF/H2O (89% for 27 and 74% for 31); (c) H2, Pd/C 10%, MeOH. A: Ring A of the lactose moiety, B: Ring B of the lactose moiety. Reagents and conditions: (a) Bu2SnO, MeOH; propargyl bromide, TBAI, Tol (92%); (b
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Published 16 Oct 2015

Multivalent polyglycerol supported imidazolidin-4-one organocatalysts for enantioselective Friedel–Crafts alkylations

  • Tommaso Pecchioli,
  • Manoj Kumar Muthyala,
  • Rainer Haag and
  • Mathias Christmann

Beilstein J. Org. Chem. 2015, 11, 730–738, doi:10.3762/bjoc.11.83

Graphical Abstract
  • ), NaH (1.1 equiv), 6-chloro-1-hexyne (1.3 equiv), TBAI (0.01 equiv), DMF, 25 °C, 16 h, 88%. Initial screening on the Friedel–Crafts alkylation of N-methylpyrrole (11) with trans-cinnamaldehyde (12).a Influence of temperature in the Friedel–Crafts alkylation.a Catalyst loading study.a Dilution
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Published 12 May 2015

Synthesis of carbohydrate-scaffolded thymine glycoconjugates to organize multivalency

  • Anna K. Ciuk and
  • Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2015, 11, 668–674, doi:10.3762/bjoc.11.75

Graphical Abstract
  • optimized procedure employing DBU and TBAI at rt [5] over two days to deliver the protected glycothymine derivative 12 in 64% yield. The acetyl protecting groups were cleaved employing Zemplén’s procedure [30]. During work-up with acidic ionic exchange resin, surprisingly cleavage of the isopropylidene
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Published 07 May 2015

Synthesis of the furo[2,3-b]chromene ring system of hyperaspindols A and B

  • Danielle L. Paterson and
  • David Barker

Beilstein J. Org. Chem. 2015, 11, 265–270, doi:10.3762/bjoc.11.29

Graphical Abstract
  • -methylenedioxybenzene and t-butyllithium) to give ketone 17 in 84% yield (Scheme 2). Allylation of ketone 17 proved problematic with the use of strong bases such as LDA and LiHMDS, giving none of the desired product. However, the use of allyl bromide and NaH in the presence of TBAI, in THF at reflux, gave the desired
  • h, 14%. Reagents and conditions: (i) H3C(CH3O)NH·HCl, n-BuLi, THF, −78 °C, 4 h, 81%; (ii) 1-bromo-3,4-methylenedioxybenzene, t-BuLi, THF, −78 °C, 3 h, 84%; (iii) NaH, allyl bromide, TBAI, THF, 65 °C, 20 h, 95%; (iv) ethylene glycol, pTSA, toluene, reflux, 16 h, 44%; (v) OsO4, NMO, t-BuOH, H2O, THF
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Published 17 Feb 2015

Relay cross metathesis reactions of vinylphosphonates

  • Raj K. Malla,
  • Jeremy N. Ridenour and
  • Christopher D. Spilling

Beilstein J. Org. Chem. 2014, 10, 1933–1941, doi:10.3762/bjoc.10.201

Graphical Abstract
  • ) failed to react at all with methyl acrylate under similar conditions, even with higher catalyst loading and extended reaction times. Initially, the synthesis of the allyl vinylphosphonate esters was achieved using a transesterification reaction catalysed by tetra n-butylammonium iodide (TBAI) (Scheme 5
  • ) [28]. A solution of the vinylphosphonate 12b, 1.1 equivalents of allyl bromide and 5 mol % TBAI in toluene was heated at reflux for 7 hours to give a 53% conversion to both the mono- and diallyl vinylphosphonates 14a and 14b in a 10:1 ratio. The overall conversion could be improved with excess allyl
  • bromide, increasing the amount of TBAI and prolonged heating times, either at reflux or in a microwave reactor. The ratio of di- to mono-allyl phosphonate esters increases with the duration of reaction. A subsequent reaction of vinylphosphonate 12b employing 5 equivalents of allyl bromide, 5 mol % TBAI
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Published 19 Aug 2014

Atherton–Todd reaction: mechanism, scope and applications

  • Stéphanie S. Le Corre,
  • Mathieu Berchel,
  • Hélène Couthon-Gourvès,
  • Jean-Pierre Haelters and
  • Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2014, 10, 1166–1196, doi:10.3762/bjoc.10.117

Graphical Abstract
  • TBAB (tetrabutylammonium bromide), TBAI (tetrabutylammonium iodide), TMAC (tetramethylammonium chloride) or 18-crown-6. The best result was obtained with TBAB and 18-crown-6 catalysts in a CH2Cl2/water or AcOEt/water mixture (yields included from 72 to 85%). The carbamate anion is another nucleophilic
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Published 21 May 2014

Synthesis of new enantiopure poly(hydroxy)aminooxepanes as building blocks for multivalent carbohydrate mimetics

  • Léa Bouché,
  • Maja Kandziora and
  • Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 213–223, doi:10.3762/bjoc.10.17

Graphical Abstract
  • of the carbonyl group and deprotection. Conditions: a) NaBH4, EtOH, 0 °C, 40 min to 16 h; b) TBAF (1 M THF), THF, 0 °C, 10 min to 3.5 h. [TBAF = tetra-n-butylammonium fluoride] Synthesis of propargylic ether 18. Conditions: a) propargyl bromide, NaOH, TBAI, H2O/CH2Cl2, −20 °C → rt, 7 d; b) NaBH4
  • , EtOH, 0 °C, 4 h; c) TBAF (1 M THF), THF, 0 °C → rt, 3 d. [TBAI = tetra-n-butylammonium iodide] Synthesis of tricyclic compound 20, bicyclic azide 24 and bicyclic amine 25. Conditions: a) MsCl, Et3N, CH2Cl2, 0 °C → rt, 5 h; b) NaBH4, EtOH, 0 °C, 6 to 16 h; c) NaN3, DMF, reflux, 16 to 46 h; d) Et3N, DMF
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Published 20 Jan 2014

Enantioselective synthesis of planar chiral ferrocenes via palladium-catalyzed annulation with diarylethynes

  • Yan-Chao Shi,
  • Rong-Fei Yang,
  • De-Wei Gao and
  • Shu-Li You

Beilstein J. Org. Chem. 2013, 9, 1891–1896, doi:10.3762/bjoc.9.222

Graphical Abstract
  • details, see Supporting Information File 1). Lowering the reaction temperature to 60 °C, excellent enantioselectivity (97% ee) could be obtained, but with a decreased yield as the starting material was not fully consumed (entry 12, Table 1). When TBACl (entry 14, Table 1) or TBAI (entry 15, Table 1) was
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Published 18 Sep 2013

Synthesis of mucin-type O-glycan probes as aminopropyl glycosides

  • David Benito-Alifonso,
  • Rachel A. Jones,
  • Anh-Tuan Tran,
  • Hannah Woodward,
  • Nichola Smith and
  • M. Carmen Galan

Beilstein J. Org. Chem. 2013, 9, 1867–1872, doi:10.3762/bjoc.9.218

Graphical Abstract
  • % overall yield. The sequence involved temporary protection of the free hydroxy at C-3 by reaction with acetic anhydride and pyridine, SN2 displacement of the chloride in monosaccharide 9 with n-tetrabutylammonium iodide (n–TBAI) in refluxing acetonitrile followed by the addition of NaN3. Ester removal was
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Published 13 Sep 2013

Iron-catalyzed decarboxylative alkenylation of cycloalkanes with arylvinyl carboxylic acids via a radical process

  • Jincan Zhao,
  • Hong Fang,
  • Jianlin Han and
  • Yi Pan

Beilstein J. Org. Chem. 2013, 9, 1718–1723, doi:10.3762/bjoc.9.197

Graphical Abstract
  • reactions. Additionally, metal-free methodologies, which use TBHP, PhI(OAc)2, TBAI, I2 or Lewis/Brønsted acids, have also been employed for cross-dehydrogenative coupling reactions [48][49][50][51][52][53][54][55][56][57]. Owing to the general low reactivity of cycloalkane C(sp3)–H bonds, the direct
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Published 21 Aug 2013

Glycosylation efficiencies on different solid supports using a hydrogenolysis-labile linker

  • Mayeul Collot,
  • Steffen Eller,
  • Markus Weishaupt and
  • Peter H. Seeberger

Beilstein J. Org. Chem. 2013, 9, 97–105, doi:10.3762/bjoc.9.13

Graphical Abstract
  • functionalized with linker 1 (Scheme 4). Coupling to both chloro-functionalized Merrifield resin 16 and Jandajel 17 was achieved by a tetrabutylammonium iodide (TBAI) mediated substitution in the presence of Cs2CO3. Capping of unreacted chlorides by cesium acetate and subsequent acidic hydrolysis of the THP
  • 2 steps; (f) TFA, DCM, rt, 99%; (g) NHS, DCC, DMAP, CH3CN, DCM, rt, 63%; (h) 2 M aq NaOH, THF, 55 °C, 92%; (i) p-TsOH·H2O, MeOH, DCM, rt, 94%; (j) Pd(OAc)2, HCOONH4, MeOH, H2O, 90%. Coupling of linker 1 to different resins. Reactions and conditions: (a) 1. 1 and 16 or 17, Cs2CO3, DMF, TBAI, 60 °C; 2
  • . CsOAc, TBAI, DMF, 60 °C; 3. p-TsOH·H2O, MeOH, DCM, rt; (b) 1. 1 and 18, 19, 20, 21 or 22, HOBt, DIC, DMF, rt; 2. Ac2O, pyridine, DCM, rt; 3. p-TsOH·H2O, MeOH, DCM, rt; (c) 1. 2 and 18, 19, 20 or 22, pyridine, DCM, rt; 2. Ac2O, pyridine, DCM, rt; 3. 1, Cs2CO3, DMF, TBAI, 60 °C; 4. CsOAc, TBAI, DMF, 60 °C
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Published 16 Jan 2013

Acylsulfonamide safety-catch linker: promise and limitations for solid–phase oligosaccharide synthesis

  • Jian Yin,
  • Steffen Eller,
  • Mayeul Collot and
  • Peter H. Seeberger

Beilstein J. Org. Chem. 2012, 8, 2067–2071, doi:10.3762/bjoc.8.232

Graphical Abstract
  • -TsOH·H2O, DCM, 86%; (g) LiOH·H2O, THF/H2O, reflux, 95%; (h) 4-sulfamoylbenzoic acid, DCC, DMAP, DCM/DMF, 60%. Functionalization of different resins. Reagents and conditions: (a) Cs2CO3, DMF, TBAI, Merrifield chloride resin; (b) CsOAc, DMF, TBAI; (c) p-TsOH·H2O, MeOH; (d) DIC, HOBt, DCM, Merrifield amine
  • resin; (e) Ac2O, pyridine; (f) (COCl)2, DMF (cat), 99%; (g) TentaGel amine resin, DCM, pyridine, then Ac2O; (h) 10, Cs2CO3, DMF, TBAI. Glycosylation and cleavage reactions for analysis. Reagents and conditions: (a) automated glycosylations using 17, 18 or 19; (b) NaOMe, MeOH. Further investigations of
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Published 26 Nov 2012

Enantioselective total synthesis of (R)-(−)-complanine

  • Krystal A. D. Kamanos and
  • Jonathan M. Withey

Beilstein J. Org. Chem. 2012, 8, 1695–1699, doi:10.3762/bjoc.8.192

Graphical Abstract
  • the obscuraminols [2]. Such synthetic studies are currently underway in our laboratory. Experimental Undeca-5,8-diyn-1-ol (2): To a suspension of anyhydrous Cs2CO3 (9.19 g, 28.2 mmol), TBAI (10.39 g, 28.2 mmol) and CuI (5.37 g, 28.2 mmol) in anhydrous DMF (60 mL) was added 5-hexyn-1-ol (3.11 mL, 28.2
  • . Retrosynthetic analysis of (R)-(−)-complanine. Reagents and conditions: (a) Cs2CO3, CuI, TBAI, DMF, rt, 24 h, 91%; (b) H2 (1 atm), Lindlar catalyst, EtOAc, pyridine, rt, 24 h; (c) DMSO, (COCl)2, DCM, −78 °C, then; 1, −78 °C, 45 min, then, Et3N, 0 °C, 1.5 h, 86% from 2. Direct approach to amino alcohol 4
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Published 04 Oct 2012

Studies on the substrate specificity of a GDP-mannose pyrophosphorylase from Salmonella enterica

  • Lu Zou,
  • Ruixiang Blake Zheng and
  • Todd L. Lowary

Beilstein J. Org. Chem. 2012, 8, 1219–1226, doi:10.3762/bjoc.8.136

Graphical Abstract
  • ) TBDPSCl, imidazole, DMF, 78%; (b) BnBr, NaH, TBAI, 84%; (c) TBAF, THF, 83%; (d) CH3I, NaH, DMF, 87%; (e) HO-P(O)(OBn)2, NIS, AgOTf, CH2Cl2, 70%; (f) H2, Pd(OH)2–C, NaHCO3, CH3OH, 91%. Reagents and conditions: (a) Ag2O, CaSO4, CH3I, 52%; (b) Ac2O–HOAc–H2SO4, 70:30:1, 96%; (c) EtSH, BF3·OEt2, CH2Cl2, 75
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Published 01 Aug 2012
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