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

• groups free [14][15]. The following Williamson etherification [16] with propargyl bromide yielded the 2,3-di-O-propargylmannoside 3 in high yield. Propargylation was selected for this step to allow eventual conjugation with the known azidopropylated thymine derivative 6 [17][18][19][20] via copper(I

A simple and efficient method for the preparation of 5-hydroxy-3-acyltetramic acids

• Johanna Trenner and
• Evgeny V. Prusov

Beilstein J. Org. Chem. 2015, 11, 323–327, doi:10.3762/bjoc.11.37

• hemiaminal ethers by simple heating them with the corresponding alcohol (Scheme 2). Etherification with methanol, ethanol and 2-trimethylsilylethanol produced the hemiaminal ethers in almost quantitative yields. We next investigated the deprotection of the so obtained hydroxylated derivatives. Several

Electrochemical selenium- and iodonium-initiated cyclisation of hydroxy-functionalised 1,4-dienes

• Philipp Röse,
• Steffen Emge,
• Jun-ichi Yoshida and
• Gerhard Hilt

Beilstein J. Org. Chem. 2015, 11, 174–183, doi:10.3762/bjoc.11.18

• in electrochemical reactions using selenium cations. Several methods applying electrochemically generated selenium cations with alkenes or alkynes including seleno-etherification and lactonisation, epoxidation and oxoselenylation sequences have been reported in the last decades [20][21][22][23][24

• the halonium source. Several reactions using bromonium- and iodonium cations such as iodo-etherification, lactonisation or Friedel–Crafts alkylation reactions can be found in literature. However, these procedures often use expensive or toxic halonium sources like molecular bromine [10][28][29] or

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

• compounds [15], the Pd(II)-catalyzed oxidative C–C, C–O, and C–N bond formation [3], the transition metal-catalyzed etherification of unactivated C–H bonds [19], the Pd(II)-catalyzed oxidative functionalization at the allylic position of alkenes [20][21], the oxidative functionalization catalyzed by copper

Synthesis of uniform cyclodextrin thioethers to transport hydrophobic drugs

• Lisa F. Becker,
• Dennis H. Schwarz and
• Gerhard Wenz

Beilstein J. Org. Chem. 2014, 10, 2920–2927, doi:10.3762/bjoc.10.310

• displacement reactions starting from the corresponding per-(6-deoxy-6-bromo)cyclodextrins. Further modification of all 2-OH positions by etherification with iodo terminated triethylene glycol monomethyl ether (and tetraethylene glycol monomethyl ether, respectively) furnished water-soluble hosts. Especially

Facile synthesis of 1-alkoxy-1H-benzo- and 7-azabenzotriazoles from peptide coupling agents, mechanistic studies, and synthetic applications

• Mahesh K. Lakshman,
• Manish K. Singh,
• Mukesh Kumar,
• Raghu Ram Chamala,
• Vijayender R. Yedulla,
• Domenick Wagner,
• Evan Leung,
• Lijia Yang,
• Asha Matin and
• Sadia Ahmad

Beilstein J. Org. Chem. 2014, 10, 1919–1932, doi:10.3762/bjoc.10.200

• appeared implausible on the basis of prior observations, where no reaction of BOP with the free hydroxy groups of nucleosides was observed [23][25]. Our recent work on a two-step one-pot etherification of purine nucleosides, quinazoline, and pyrimidines, had led some interesting preliminary observations

Investigations of thiol-modified phenol derivatives for the use in thiol–ene photopolymerizations

• Sebastian Reinelt,
• Monir Tabatabai,
• Urs Karl Fischer,
• Norbert Moszner,
• Andreas Utterodt and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 1733–1740, doi:10.3762/bjoc.10.180

• the reaction sequence and yielded compound 3. The quantitative etherification of the phenolic hydroxy groups with potassium carbonate and ethyl iodide yielded the corresponding ether derivative 5. Subsequently the remaining hydroxy groups of 3 and 5 were o-alkylated in the presence of a strong base

• etherification, which was conducted in analogy to a procedure described in literature [40], as demonstrated in Scheme 2. Bisphenol A, bisphenol S and the trisphenol derivative 1,1,1-tris(4-hydroxyphenyl)ethane were chosen as basic structures. Subsequently, the successful radical addition of thioacetic acid (8

Postsynthetic functionalization of glycodendrons at the focal point

• Thisbe K. Lindhorst and
• Katharina Elsner

Beilstein J. Org. Chem. 2014, 10, 1482–1487, doi:10.3762/bjoc.10.152

• etherification, thiol-ene reaction and in particular olefin cross metathesis. Keywords: amphiphilic glycomimetics; cross metathesis; glycodendrons; multivalent glycoconjugates; multivalent glycosystems; Introduction In addition to nucleic acids and proteins, molecular life is based on a third important class

• Discussion The principal synthesis of the employed polyether glycodendrons has been published earlier by us [7][8]. It is based on Williamson etherification of methallyldichloride (MDC, 1, 3-chloro-2-chloromethyl-1-propene) [9] using the isopropylidene-protected hydroxyethyl mannoside 2 to furnish the

• etherification reaction with MDC to deliver glycodendron 7 of the next dendron generation. This in turn, can be further elaborated to give the alcohol 8 and the formerly unknown glycodendron alkene 9. Initially, postsynthetic focal point modification of glycodendrons was attempted by direct etherification

Carbohydrate PEGylation, an approach to improve pharmacological potency

• M. Eugenia Giorgi,
• Rosalía Agusti and
• Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2014, 10, 1433–1444, doi:10.3762/bjoc.10.147

• from N-phthaloylchitosan by etherification with poly(ethylene glycol) monomethyl ether (mPEG) iodide obtaining different degrees of O-substitution [56]. Several strategies were designed to obtain regioselective PEGylation at C-6 of the glucosamine unit [57]. Other methods of PEGylation included, among

End-group-functionalized poly(N,N-diethylacrylamide) via free-radical chain transfer polymerization: Influence of sulfur oxidation and cyclodextrin on self-organization and cloud points in water

• Sebastian Reinelt,
• Daniel Steinke and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 680–691, doi:10.3762/bjoc.10.61

• -diethylacrylamide) has not been investigated. Results and Discussion Synthesis of thiol functionalized 4-alkylphenols. As depicted in Scheme 1, the synthesis of the thiol-functionalized phenol derivatives was accomplished in a three step synthesis. Etherification of the phenolic hydroxy groups of 1a and 1b with

Concise, stereodivergent and highly stereoselective synthesis of cis- and trans-2-substituted 3-hydroxypiperidines – development of a phosphite-driven cyclodehydration

• Peter H. Huy,
• Julia C. Westphal and
• Ari M. P. Koskinen

Beilstein J. Org. Chem. 2014, 10, 369–383, doi:10.3762/bjoc.10.35

• catalytically active batches and freshly prepared Pd/C [77] led to quantitative conversion within 1–2 d (1 atm H2). The resulting alcohol cis-16c was subjected to Williamson etherification and subsequently the Boc-group was cleaved under acidic conditions (HCl in dioxane). We decided to isolate L-733,060 as its

Synthesis and determination of the absolute configuration of (−)-(5R,6Z)-dendrolasin-5-acetate from the nudibranch Hypselodoris jacksoni

• I. Wayan Mudianta,
• Victoria L. Challinor,
• Anne E. Winters,
• Karen L. Cheney,
• James J. De Voss and
• Mary J. Garson

Beilstein J. Org. Chem. 2013, 9, 2925–2933, doi:10.3762/bjoc.9.329

• characterization of 1, in particular the configuration at C-5. The synthesis, which was completed in five steps, involved preparation of 3-furylmethanol (4) and of geranyl bromide (5), etherification, [1,2]-Wittig rearrangement of geranyl 3-furylmethyl ether (6) to produce 7a/b, and acetylation to obtain target 1

• triphenylphosphine in 90% yield. The 1H NMR spectrum of the geraniol sample used indicated the presence of traces of nerol, the Z-isomer of geraniol. Etherification of furan-3-ylmethanol (4) with the geranyl/neryl bromide mixture (5) in the presence of NaH furnished the 3-furylmethyl ether 6 (65% yield) as an E/Z

Triphenylene discotic liquid crystal trimers synthesized by Co₂(CO)₈-catalyzed terminal alkyne [2 + 2 + 2] cycloaddition

• Bin Han,
• Ping Hu,
• Bi-Qin Wang,
• Carl Redshaw and
• Ke-Qing Zhao

Beilstein J. Org. Chem. 2013, 9, 2852–2861, doi:10.3762/bjoc.9.321

• (pentyloxy)triphenylene, according to a simplified one-pot method [52]. The undec-10-yn-1-yl p-toluenesulfonate was prepared by LiAlH4 reduction of the acid and tosylation of the alcohol [53][54]. Then monomers 2 and 3a–c were synthesized by the direct esterification or etherification reaction between phenol

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

Gold-catalyzed glycosidation for the synthesis of trisaccharides by applying the armed–disarmed strategy

• Abhijeet K. Kayastha and
• Srinivas Hotha

Beilstein J. Org. Chem. 2013, 9, 2147–2155, doi:10.3762/bjoc.9.252

• . Subsequently, the disarmed disaccharide 3 was transformed into an armed glycosyl donor 4 by simple saponification followed by etherification. The reaction between armed donor 4 and disarmed aglycon 2, which was carried out under the aforementioned conditions did not result in the formation of desired

• allowed to react with disarmed aglycon 22 in the presence of AuCl3 (5 mol %)/AgSbF6 (5 mol %) in CH3CN/CH2Cl2 (1:1) at 25 °C for 4 h to obtain the disarmed disaccharide 23 in 85% yield. Further, the armed disaccharide 24 was synthesized from 23 by saponification followed by the etherification in 84% over

Gold(I)-catalysed one-pot synthesis of chromans using allylic alcohols and phenols

• Eloi Coutant,
• Paul C. Young,
• Graeme Barker and
• Ai-Lan Lee

Beilstein J. Org. Chem. 2013, 9, 1797–1806, doi:10.3762/bjoc.9.209

• have recently shown that gold(I) can catalyse a direct allylic etherification [52][53][54][55][56][57][58][59] of unactivated alcohols 2 with unactivated allylic alcohols 1 (Scheme 1, reaction 1) [60][61]. The reaction is mild, regioselective, and produces only water as a byproduct. During our studies

• etherification of allylic alcohols. Proposed pathway. Control reactions. Reaction of 21 with added Brønsted acid co-catalyst. Suggested mechanism. Initial temperature and equivalents screens, and control reactions. Phenol nucleophile scope. Allylic alcohol scope. Supporting Information Supporting Information

Re₂O₇-catalyzed reaction of hemiacetals and aldehydes with O-, S-, and C-nucleophiles

• Wantanee Sittiwong,
• Michael W. Richardson,
• Charles E. Schiaffo,
• Thomas J. Fisher and
• Patrick H. Dussault

Beilstein J. Org. Chem. 2013, 9, 1526–1532, doi:10.3762/bjoc.9.174

• dithioacetals. Reactions of hemiacetals with nitrogen nucleophiles are unsuccessful. 1,2-Dioxolan-3-ols (peroxyhemiacetals) undergo Re(VII)-promoted etherification but not allylation. Hydroperoxyacetals (1-alkoxyhydroperoxides) undergo selective exchange of the alkoxide group in the presence of either Re2O7 or

• ], we needed to prepare a number of 3-alkoxy-1,2-dioxolanes. Brønsted acid-promoted etherification of hemiacetals (1,2-dioxolan-3-ols) required harsh conditions and proceeded in good yields only for unhindered alcohols [18]. We were curious whether Re2O7, a catalyst known to activate alcohols via a

• reversibly formed Re(VII) ester [19][20], would enable displacement under milder conditions, potentially allowing access to a broader range of alkoxydioxolanes. As shown in Table 1, the use of Re2O7 or p-toluenesulfonic acid monohydrate (PTSA) as catalysts provided comparable yields in the etherification of

Superstructures of fluorescent cyclodextrin via click-reaction

• Arkadius Maciollek,
• Helmut Ritter and
• Rainer Beckert

Beilstein J. Org. Chem. 2013, 9, 827–831, doi:10.3762/bjoc.9.94

• fluorescent nature [1][2]. These optical properties can be used for the development of sensor molecules, blue emitting dyes, luminescent materials or as donor–(π-conjugated-bridge)–acceptor-type dyes in dye-sensitized solar cells [3][4][5]. The etherification of 4-hydroxythiazole by using propargyl bromide

Synthesis of functionalized macrocyclic derivatives of trioxabicyclo[3.3.0]nonadiene

• Sabine Leber,
• Gert Kollenz and
• Curt Wentrup

Beilstein J. Org. Chem. 2012, 8, 738–743, doi:10.3762/bjoc.8.83

• with 3-bromopropanol followed by nitration of the resulting diol 6 (Scheme 2). The isomeric 1,2,3-trisubstituted aromatic 10 was obtained by etherification of nitroresorcinol (Scheme 3). The two diols 7 and 10 reacted readily with the diacid dichloride 3 in boiling toluene in the presence of

Carbasugar analogues of galactofuranosides: α-O-linked derivatives

• Jens Frigell and
• Ian Cumpstey

Beilstein J. Org. Chem. 2010, 6, 1127–1131, doi:10.3762/bjoc.6.129

• exemplify the method. Keywords: carbasugars; etherification; galactofuranose; glycomimetics; pseudodisaccharides; regioselective; Introduction Galactofuranose is found in nature as a component of glycoconjugates in many microorganisms [1][2]. Galactofuranosides with the α configuration are rather less

Novel 2-(ω-phosphonooxy-2-oxaalkyl)acrylate monomers for self-etching self-priming one part adhesive

• Joachim E. Klee and
• Uwe Lehmann

Beilstein J. Org. Chem. 2010, 6, 766–772, doi:10.3762/bjoc.6.95

• acrylate and formaldehyde, and subsequent etherification of the obtained product with diols and phosphorylation using POCl3. The polymerization enthalpy of 2-(ω-phosphonooxy-2-oxaalkyl)acrylates 3 as measured by DSC ranges from −29 to −53 kJ·mol−1. The shear bond strength of adhesive compositions 4

• , comprising of phosphoric acid ester moieties, were synthesized via a three step synthesis via Baylis–Hillman reaction of ethyl acrylate and formaldehyde, and subsequent etherification of the obtained product with diols and phosphorylation using POCl3 (Scheme 1, Table 1). The double bonds in 3 are evident in

• -phosphonooxy-2-oxaalkyl)acrylate monomers 3 with phosphoric acid moieties and alkyl as well as oxyalkyl spacers were synthesized in three steps via Baylis–Hillman reaction of ethyl acrylate and formaldehyde, and subsequent etherification of the obtained product with diols and phosphorylation using POCl3. The

Synthesis of bis(3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoyl)(phenyl)phosphine oxide – a tailor-made photoinitiator for dental adhesives

• Norbert Moszner,
• Iris Lamparth,
• Jörg Angermann,
• Urs Karl Fischer,
• Frank Zeuner,
• Thorsten Bock,
• Robert Liska and
• Volker Rheinberger

Beilstein J. Org. Chem. 2010, 6, No. 26, doi:10.3762/bjoc.6.26

• ) was synthesized starting from 3-(chloromethyl)-2,4,6-trimethylbenzoic acid by the dichlorophosphine route. The substituent was introduced by etherification with 2-(allyloxy)ethanol. In the second step, 3-{[2-(allyloxy)ethoxy]methyl}-2,4,6-trimethylbenzoic acid was chlorinated. The formed acid chloride

• in acetonitrile (10−3 mol/L). DSC-plot of a mixture of Bis-GMA (42 wt %), UDMA (37 wt %), TEGDMA (21 wt %) and the PI WBAPO or BAPO. Bisacylphosphine oxide with improved solubility in polar solvents. Etherification of 3-(chloromethyl)-2,4,6-trimethylbenzoic acid and chlorination of 1. Rearrangement

Low temperature enantiotropic nematic phases from V-shaped, shape-persistent molecules

• Matthias Lehmann and
• Jens Seltmann

Beilstein J. Org. Chem. 2009, 5, No. 73, doi:10.3762/bjoc.5.73

• nematogens were prepared following the recent optimised procedure [25], using the mono-protected diethynylbenzene derivative 4 as a key compound (Scheme 1). The peripheral aromatic units 5 were obtained by etherification of 4-iodophenol with the corresponding ethyl ω-bromoalkanoate [28]. Cross-coupling of

Ring strain and total syntheses of modified macrocycles of the isoplagiochin type

• Andreas Speicher,
• Timo Backes,
• Kerstin Hesidens and
• Jürgen Kolz

Beilstein J. Org. Chem. 2009, 5, No. 71, doi:10.3762/bjoc.5.71

• simple modification, e. g. etherification. However, the flexibility and stability of the molecule is only slightly modified by introducing an unsaturated two-carbon bridge between rings b and c. Structures of isoplagiochins C (1) and D (2) (with aryl fragments a–d and possible conformational barriers A–D

Influence of spacer chain lengths and polar terminal groups on the mesomorphic properties of tethered 5-phenylpyrimidines

• Gundula F. Starkulla,
• Elisabeth Kapatsina,
• Angelika Baro,
• Frank Giesselmann,
• Stefan Tussetschläger,
• Martin Kaller and
• Sabine Laschat

Beilstein J. Org. Chem. 2009, 5, No. 63, doi:10.3762/bjoc.5.63

• 55, 70569 Stuttgart, Germany 10.3762/bjoc.5.63 Abstract Based on 5-(4-hydroxyphenyl)-2-octylpyrimidine 8, 5-phenylpyrimidine derivatives 3–7, 9 with different spacer chain lengths (C2 up to C6) and different terminal polar groups (Br, Cl, N3, OH, CN) were synthesized by etherification and

• 23 up to 60% yield. When 1,3-dibromopropane was used, 27% of the elimination product 9 was isolated as byproduct. For comparison the corresponding 4-allyloxy-4′-octylbiphenyl 11 was prepared in 49% yield by allylation of 4-hydroxy-4′-octylbiphenyl. Compound 3a was obtained by etherification of 5-(4