bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidationen an Thiourethanen, 10. Synthese, Kristallstruktur, Oxidation und Photochemie der Thion‐S‐oxide cyclischer Dithiourethane und Dithiocarbazate
Authors: Hanefeld Wolfgang , Schlitzer Martin , Schütz Harald , Wocadlo Sigrid , Massa Werner 
Published: July 2007

Oxidations of Thiourethanes, 10. — Synthesis, Crystal Structure, Oxidation and Photochemistry of Thione S‐Oxides of Cyclic Dithiourethanes and DithiocarbazatesSeveral cyclic dithiocarbamates and dithiocarbazates (2–4) have been oxidised with mCPBA to give the corresponding thione S‐oxides 5–7. The sulfine structure was confirmed by oxidation to the corresponding oxo derivatives and X‐ray crystal structure analysis. Photolysis of the sulfines gave the corresponding oxo as well as the thioxo derivatives. The isolation of both the oxo and the thioxo derivatives is reported here for the first time, it provides an other evidence for the postulated thioxirane intermediate in the photolysis of sulfines.
Synthesen und Umsetzungen von 2,6‐Epoxy‐4H‐3‐benzoxocin‐4‐onen
Authors: Wünsch Bernhard , Bauschke Gerd 
Published: July 2007

Syntheses and Transformations of 2,6‐Epoxy‐4H‐3‐benzoxocin‐4‐onesFour variations for the preparation of 5 are described: acid‐catalyzed cyclisation of the methoxy acid 4a, base‐catalyzed lactonisation of the hydroxy ester 6b, DCC‐mediated dehydration of the hydroxy acid 6a and PCC oxidation of the hemiacetals 17a and 17b. By three steps the key intermediate 4a is prepared by addition of the lithium enolate of methyl acetate to the aldehyde 7 with subsequent cyclisation and saponification. Alternatively, addition of the acetic acid dianion to 7 followed by acidic work‐up yields 4a in a one‐pot procedure. Hydrolysis of 4a and 4b with dilute HCl gives the hemiacetals 6a and 6b, respectively. After deprotonation with LDA, 5b reacts with CH3I and aldehydes to afford the 5‐substituted epoxybenzoxocinones 18 and 20.
Asymmetric Synthesis via Heterocyclic Intermediates, XLVII. Asymmetric Synthesis of (+)‐(1R,2S)‐allo‐Coronamic Acid
Authors: Groth Ulrich , Halfbrodt Wolfgang , Schöllkopf Ulrich 
Published: July 2007

Abstractallo‐Coronamic acid (1) was synthesized in five steps enantiomerically and diastereomerically virtually pure by starting from the bislactim ethers of cyclo(‐L‐Val‐Gly‐) (3a) or cyclo‐(‐L‐tert‐Leu‐Gly‐) (3b) in an overall yield of 31%. The key step of this synthesis is the intramolecular alkylation of the lithium azaenolate derived from the allylic chloride 4.
Totalsynthese von Thymosin β4, 2. Klassische Synthese des Fragments [20–30] von Thymosin β4
Authors: Kapurniotu Afroditi , Voelter Wolfgang 
Published: July 2007

Total Synthesis of Thymosin β4, 2. — Conventional Synthesis of the Fragment [20–30] of Thymosin β4As part of the total synthesis of thymosin β4 three synthetic pathways for the synthesis of the thymosin β4 fragment [20–30] are described. The side‐chain functions are protected by tert‐butyl and the α‐amino residues by Z groups. As temporary protection of the carboxyl function the phenyl ester is successfully used.
Syntheses of Some Biologically Active Compounds from Stilbenes Isolated from the Bark of Picea abies
Authors: Talvitie Antti , Mannila Erkki , Kolehmainen Erkki 
Published: July 2007

AbstractFrom the four stilbenes 1–4 isolated from the bark of Picea abies seven compounds 5–11 were obtained by hydrogenation or permethylation. 1H‐, 13C‐NMR and mass spectra were used for their characterization. The antileukemic activity of each compound was preliminary tested. Some compounds were further tested for their anti‐HIV activity.
Thiazol‐ und Thiazolidin‐Derivate aus Benzoylthioharnstoffen
Authors: Wobig Dieter 
Published: July 2007

Derivatives of Thiazoles and Thiazolidines from BenzoylthioureasThe thioureas 1a–c react with the derivatives of γ‐bromocrotonic acid 2a and 2b to give the thiazoles 3a–f. Contrary to this, the treatment of 1d or 1e with 4 or 2a and 2b leads to the thiazolidines 5a and 5b or 6a–d, respectively. 3g can be synthesized by the reaction of N‐benzimidoyl‐N′‐phenylthiourea (7) with 2a.
4,4′‐Bis(dimethylamino)benzophenon (Michlers Keton) — ein universeller Indikator zur Bestimmung der Acidität, Dipolarität und Polarisierbarkeit von Reaktionsmedien
Authors: Spange Stefan , Keutel Dietmar 
Published: July 2007

4,4′‐Bis(dimethylamino)benzophenone (Michler's Ketone) — a Common Indicator of the Acidity and Dipolarity/Polarizability of Reaction MediaThe solvatochromisms of Michler's Ketone (1) and the iron (II) complex Fe(phen)2(CN)2 (2) has been investigated in 73 solvents of different polarity. The solvent‐induced UV/Vis‐absorption shifts of 1 and 2 are mainly attributed to both the hydrogen‐bond donor acidity and dipolarity/polarizability of the solvent as verified by a Kamlet‐Taft correlation analysis and comparison with common solvent‐polarity scales such as Reichardt's ET(30) values and the acceptor scale of Gutmann. Michler's Ketone exhibits the largest positive solvatochromism known so far. The specific role of phenolic solvents has been discussed with regard to a charge‐transfer complexation between the positively polarized ring of 1, caused by the hydrogen‐bond formation at the carbonyl oxygen, and the aromatic ring of the phenol.
Biogenetic Studies on Oxazolomycin, a Metabolite of Streptomyces albus (Strain JA 3453)
Authors: Gräfe Udo , Kluge Heinz , Thiericke Ralf 
Published: July 2007

AbstractFeeding experiments with sodium [13C]‐labelled acetate, sodium [1‐13C]propionate, L‐[methyl‐13C]methionine, L‐[1‐13C]‐alanine, and [1‐13C]glycine on Streptomyces albus (strain JA 3453) produced oxazolomycin (1), whose NMR analysis provided information about the biogenetic construction of its carbon skeleton. Both the (E,E)‐diene and the (Z,Z,E)‐triene chains are built up from acetate via the polyketide pathway each starting with a glycine‐derived building block. The use of glycine predicts an uncommon biosynthetic pathway leading to oxazole rings in actinomycetes. The spiro‐ring system in 1 is formed from acetate, glycine, and a C3 unit of unknown origin. The oxazolomycin producing organism combines carbon, oxygen, and nitrogen methylation activity via methionine (C1 pool) for the biosynthesis of 1.
Thermal Degradation of Glycosides, V. Hydrothermolysis of Triterpenoid and Steroid Glycosides
Authors: Kim Youn Chul , Higuchi Ryuichi , Komori Tetsuya 
Published: July 2007

AbstractIn this paper the hydrothermolysis of triterpenoid and steroid glycosides is described. By mere heating with water or water/1,4‐dioxane solution, the triterpenoid and steroid glycosides 1, 4 and 15, 16, 25, 29, respectively, are converted into their aglycones and prosapogenins. Furthermore, hydrothermolysis of the triterpenoid 3,28‐O‐bisglycosides 5, 6, 8, 9, 12 affords the corresponding 3‐O‐glycosides and reduced oligosaccharides formed by selective cleavage of the ester glycosidic linkage. It is expected that this hydrothermolysis is useful for the structure determination of some triterpenoid and steroid glycosides and for yielding new oligosaccharides. The hydrothermolyzed products have been isolated by chromatography and their structures elucidated by spectroscopic methods.
Versuche zur Synthese von Strychnopivotin und eine einfache Synthese des Isochinuclidin‐Gerüsts
Authors: Teuber Hans‐Joachim , Tsaklakidis Christos , Bats Jan Willem 
Published: July 2007

Experiments Directed to the Synthesis of Strychnopivotine and a New Synthesis of the Isoquinuclidine FrameworkThe 2‐azabicyclo[3.3.1]nonane (keto‐morphane) 2 can be transformed via the enamine 4 into the dithio‐dioxolane derivative 6 of the corresponding 6,7‐diketone. After hydrolysis of the dithio group and formation of the monoprotected diketone 3 Fischer cyclisation yields the isodasycarpidone derivative 7, an intermediate to a synthesis of strychnopivotine (1a). — In view of the likewise desired tricyclus 8 for a synthesis of strychnopivotine, a cyclisation of ketoamide 9 was tried under standard conditions. By aldol‐ring closure, however, not the expected 2‐azabicyclo[3.3.1]nonane 14 was formed, but instead the 2‐azabicyclo[2.2.2]octane derivative (isoquinuclidine) 15. The preparation of 9 via the intermediates 10–13 is described.
Kondensierte 1.2‐Dithiole, I. Synthese von Thiolutin und verwandten Verbindungen
Authors: Stachel Hans‐Dietrich , Nienaber Juliane , Zoukas Thomas 
Published: July 2007

Ring‐Fused 1,2‐Dithioles, I. — Synthesis of Thiolutine and Related CompoundsThe 1,2‐dithiolopyrrole 1 (thiolutine) has been obtained on two different routes. Firstly, by synthesis of the dithiolopyrrole 6a and introduction of the acetamino function into compound 6d by nitration followed by ester saponification and decarboxylation. 6d is also available from 9k by oxidative ring contraction which occurs with simultaneous dealkylation of the benzylamino group. Secondly, by synthesis of the dithiinopyrrole 15b and introduction of the acetamino function into compound 15g by Beckmann rearrangement followed by ring contraction.
Bausteine von Oligosacchariden, CI. Synthese von modifizierten Oligosacchariden der N‐Glycoproteine zur Untersuchung der Substratspezifität der N‐Acetylglucosaminyltransferase II des Trimming‐Prozesses
Authors: Paulsen Hans , van Dorst Johannes A. L. M. , Reck Folkert , Meinjohanns Ernst 
Published: July 2007

Building Units of Oligosaccharides, CI. — Synthesis of Modified Oligosaccharides of the N‐Glycoproteins Intended for Substrate Specificity Studies of N‐Acetylglucosaminyltransferase II of the Trimming ProcessThe trichloroacetimidate method was very successful for the synthesis of the tetrasaccharide octyl O‐(2‐acetamido‐2‐deoxy‐β‐D‐glucopyranosyl)‐(1→2)‐O‐(α‐D‐mannopyranosyl)‐(1→3)‐O‐[(α‐D‐mannopyranosyl)‐(1→6)]‐β‐D‐mannopyranoside (10). Further derivatives of the tetrasaccharide with a 4‐O‐methyl group 20 and with a 4‐deoxy group 28 were synthesized. The tetrasaccharides are intended for substrate specificity studies of the N‐acetylglucosaminyltransferase II of the trimming process in the biosynthesis of N‐glycoproteins.
Glycosylimidates, 54. Synthesis of the GlcNAcβ(1→4)MurNAcβ(1→4)GlcNAcβ(1→4)MurNAc tetrasaccharide of bacterial peptidoglycan
Authors: Termin Andreas , Schmidt Richard R. 
Published: July 2007

AbstractFrom 2‐azido‐2‐deoxy‐D‐glucose have been prepared at 1‐O and/or 4‐O selectively protected glucosamine and muramic acid derivatives, which were transformed into glycosyl donors 6 and 14a, b and into glycosyl acceptors 7 and 15. The reaction of these donors and acceptors yielded disaccharides 8 and 11–13. Selective 1a‐O‐deprotection of disaccharide 12 and subsequent treatment with trichloroacetonitrile afforded disaccharide donor 17; selective removal of the 4b‐O‐protective groups in disaccharides 8 and 11 furnished disaccharide acceptor 9. These building blocks were employed in the synthesis of β‐connected tetrasaccharide 18 which gave upon azido group reduction, acetylation of the amino groups, and complete O‐deprotection the desired target molecule 1 characterized as its fully O‐acetylated product 2.
Regioselective Conversion of Nonactivated CH Bonds, VI. Selective ω‐ to (ω – 2)‐Chlorination of Fatty Acids by Way of Adsorption on Alumina
Authors: Hinkamp Ludger , Schäfer Hans J. , Wippich Barbara , Luftmann Heinrich 
Published: July 2007

AbstractFatty acids 4–7 can be chlorinated with high selectivity in the (ω — 2)‐ to ω‐position. For that purpose the acid is adsorbed on alumina and allowed to react with gaseous chlorine or t‐BuOCl at 20 and −35°C. The resulting chloroalkanoic acids 10–13 can be converted into macrocyclic lactones 14–17 by treatment with DBU.
Photodynamic Perylenequinones, Photodemethylation and Photooxidation of Dimethylcercosporin
Authors: Arnone Alberto , Luogo Daniela Dal Pio , Merlini Lucio , Nasini Gianluca 
Published: July 2007

AbstractRegiospecific photodemethylation of the perylenequinone dimethylcercosporin (DMC0 (2) in methanol involved the two methoxy groups in ortho position to the carbonyl quinone functions, affording 2,11‐dihydroxy‐3,10‐perylenequinone (3) and the dihydrofuran‐containing derivative 4. When irradiated in acetonitrile in the presence of oxygen 2 was converted into two photooxidation products 5 and 7 whose structure was assigned on the basis of 13C‐NMR studies.
Derivate natürlicher Tetrapyrrole für die Photodynamische Therapie, 2 Modellreaktionen zur direkten CC‐Verknüpfung von Porphyrinen
Authors: Risch Nikolaus , Mackenbrock Ursula 
Published: July 2007

Natural Tetrapyrrol Derivatives for the Photodynamic Therapy, 2. — Model Reactions for Direct C–C Linkages of PorphyrinsUntil now, there is a lack of information about the structure of the active components in the diagnosis and photodynamic therapy of cancer with hematoporphyrin derivatives (HPD). We describe the formation of HPD in terms of benzyl cation chemistry. Selective formation of the C—C‐linked model compounds 4, 5 by reaction of protoporphyrin dimethyl ester (2) with electron‐rich aromatic compounds as well as of 9—12, 15–17, obtained by reaction of the porphyrin dimethyl esters 2, 6, 7, and 8, with carbon electrophiles (preformed Mannich salts), results from this concept.
Enoletherepoxide und ihre Reaktionsprodukte mit Nucleophilen
Authors: Meyer Claudia , Spiteller Gerhard 
Published: July 2007

Enol Ether Epoxides and Products Resulting from Their Reaction with Nucleophiles1,2‐Epoxydecyl pentyl ether (9a) was synthesized by treatment of 1‐decenyl pentyl ether (5) with diemthyldioxirane (8). The enol ether epoxide 9a, characterized by its mass, 1H‐ and 13C‐NMR spectra, reacts readily with hydride, O‐, S‐ and N‐nucleophiles. Similar reactions are expected to take place in the organism after biological oxidation of plasmalogens to their epoxides. This hypothesis is verified by detection of mixed acetals after tissue workup.
Thioalkylation of enolates, II. – α‐Thioalkylation of Zinc Enolates to α,α‐Disubstituted Ketones
Authors: Groth Ulrich , Huhn Thomas , Richter Norbert 
Published: July 2007

AbstractAn α‐alkylation of the 2‐methylcycloalkanones 1 and 4 at the higher substituted carbon can be achieved by thioalkylation of the corresponding zinc enolates with the α‐chlorosulfides 3. The desulfurization can be carried out with either Raney nickel or lithium in diethylamine for compounds which contain double or triple bonds.
Steroidal cyclobutanones, III. The Synthesis and Stereochemistry of 3‐Spiro‐5α‐cholestane Derivatives with Three‐, Four‐, and Five‐membered Carbon Rings—A Double Cine Substitution in Spiro‐α,α‐dichlorocyclobutan‐3‐ones
Authors: Paryzek Zdzislaw , Błaszczyk Krzysztof 
Published: July 2007

AbstractDiastereomeric [(3S)‐5α]‐ and [(3R)‐5α]‐2′,2′‐dichlorospiro‐[cholestane‐3,1′‐cyclobutan]‐3′‐ones (1 and 2), prepared by cycloaddition reaction of dichloroketene with 3‐methylene‐5α‐cholestane, served as starting material for the synthesis of the related spirane derivatives. Thus, the synthesis of spiro‐cyclopentane (3–6), spirocyclobutane (9, 11, 13, 17–20) and spirocyclopropane steroids (12, 14, 15) is described. The sterically dependent reaction of spiro‐α,α‐dichlorocyclobutan‐3‐ones with an excess of sodium methanolate in methanol is reported. Thus, the reaction of 1 with sodium methanolate gives 9, the product of the double cine substitution, while the corresponding reaction of compound 2, which is sterically more hindered for similar nucleophilic attack, gives mainly the spirocyclopropane 12. The stereochemistry of the spiro compounds is assigned on the basis of 1H‐ and 13C‐NMR spectra.
Synthesis of (3R,4R)‐3‐Amino‐4‐hydroxyhexahydroazepine, the Chiral Constituent of the Antibiotic Ophiocordin
Authors: Müller Alexander , Takyar Dinesh K. , Witt Sandra , König Wilfried A. 
Published: July 2007

Abstract(3R,4R)‐3‐Amino‐4‐hydroxyhexahydroazepine (2), the optically active constituent of the antifungal antibiotic ophiocordin (1), was prepared in a multistep synthesis starting from D‐serine. The absolute configuration was unambigously assigned by a comparison of the synthesized stereoisomer 2 with its racemate and the chiral moiety of the antibiotic ophiocordin by enantioselective gas chromatography.
Chemical Interactions between Aminopyrazoles and 2,3‐Dicyano‐1,4‐naphthoquinone
Authors: Hassan Alaa A. , Mohamed Nasr K. , Ibrahim Yusria R. , Mourad Aboul‐Fetouh E. 
Published: July 2007

Abstract2,3‐Dicyano‐1,4‐naphthoquinone (DCNQ), the easily obtainable isomer of 2‐(dicyanomethylene)indane‐1,3‐dione (CNIND), reacts with arylazo‐, pyridylazo‐ and arylaminopyrazoles 1–3 via charge‐transfer (CT) complexation to yield pyrazolo[2,3‐α]quinazolinediones 10a–f and pyrazolo[2,3‐α]‐quinazolinyl acetates 11a–e. Furthermore, aminopyrazole 3 reacts with 2,3‐dichloronaphthoquinone (DCHNQ) to afford the naphthoquinoimidazopyrazole 13. The mechanism of the formation of products 10 and 11 is discussed.
Synthese des Azocino[4.3‐b]indol‐Grundgerüstes von Strychnos‐Alkaloiden
Authors: Fritz Helmut , Soleymani‐Jamarani Mohammad , Bats Jan Willem , Teuber Hans‐Joachim 
Published: July 2007

Synthesis of the Azocino[4.3‐b]indole Core Structure of Strychnos AlkaloidsMichael addition of ethylmalonic dimethyl or diethyl ester with cyclohexenone and subsequent Fischer indole ring closure afford the (tetrahydrocarbazolyl)malonic esters 4a–c. Decarboxylation of 4a leads to the corresponding butyric acid methyl ester 5 which is oxidized by DDQ to the 4‐oxo derivative 6a (byproduct: carbazole 7). Oximation of 6a to 8a and acylation of the oxime group to 8b, c as well as hydrogenation of this group yield 9a, b. Subsequent hydrogenation of the tetrahydrocarbazole ring by means of borane/pyridine yields the hexahydrocarbazole derivatives 10a and b. By cyclisation in boiling o‐xylene (sodium hydride catalysis) 10a is converted into the tetracyclic 1,5‐methanoazocino[4.3‐b]indole derivative 11a with an alkaloid analogous ethyl side chain. The X‐ray structural analysis of the corresponding phenylsulfonyl derivative 11b confirms constitution and stereochemistry. As a diastereoisomer of 11a the byproduct 11c could be isolated.
Asymmetric Synthesis via Heterocyclic Intermediates, LII. Synthesis of tert‐Leucine and Related Amino Acids
Authors: Groth Ulrich , Huhn Thomas , Porsch Bettina , Schmeck Carsten , Schöllkopf Ulrich 
Published: July 2007

AbstractThe 2,5‐dialkoxypyrazines 3a and b were prepared in three steps from methyl glycinate hydrochloride (1) in an overall yield of 18 and 63%. Upon the addition of lithium organyls to 3b and subsequent acidic hydrolysis the ethyl glycinates rac‐7 were obtained.
Pseudosugars, 32. – Synthesis of 1,4‐Imino‐linked Carbadisaccharides Composed of a 2‐Amino‐5a‐carba‐2‐deoxyglucopyranosylamine Residue and Its Congeners
Authors: Ogawa Seiichiro , Tsunoda Hidetoshi 
Published: July 2007

AbstractCarbadisaccharide 5, containing a 2‐acetamido‐5a‐carba‐2‐deoxyhexopyranosylamine residue, was synthesized by coupling of methyl 4‐amino‐4‐deoxy‐α‐D‐glucopyranoside (41) with the N‐(2,4‐dinitrophenyl)epimino compound 16 followed by deprotection. The 6′‐acetamido‐6′‐deoxy analog 3 of a potent α‐glucosidase inhibitor methyl acarviosin (1) was synthesized from a condensate 50 obtained by coupling of 41 with the protected epimino compound 18, possessing an exo‐methylene function. This process involves a sequence of reactions: replacement by a benzoate ion and successive dehydrobromination of the dibromide 52 obtained from 50. Hydroxymercuration of 50 followed by demetalation and deprotection gave two carbadisaccharide analogs 7 and 9 containing the valiolamine‐type branched aminocyclitol moieties. The free amines 4, 6, 8, and 10 were prepared by treatment of the corresponding N‐protected derivatives with Amberlite IRA 400 (OH−) resin. Biological assays of all carbadisaccharides were carried out with three sugar hydrolases. Only compounds 6 and 8 were shown to be very weak α‐mannosidase inhibitors. The introduction of the acetamido or amino function instead of the hydroxyl group into the C‐6′ position of the methyl acarviosin analog 2 resulted in an appreciable decrease of the inhibitory activity.
Enzymes in Organic Synthesis, 18. Lipase‐catalyzed Asymmetric Alcoholysis of 3‐Substituted Pentanedioic Anhydrides
Authors: Ozegowski Rüdiger , Kunath Annamarie , Schick Hans 
Published: July 2007

AbstractThe influence of several enzymes, alcohols, and solvents on the stereochemical outcome of the asymmetric alcoholysis of 3‐substituted pentanedioic anhydrides was investigated. The alcoholysis of 3‐acetoxypentanedioic anhydride (5a) in diethyl ether with 2‐methylpropanol afforded the (3S)‐monoester (S)‐6a with an enantiomeric excess of > 98% when the lipase from Candida sp. 382 was used as the enzyme. Under the same conditions, 3‐methoxypentanedioic anhydride (5c) was converted by the lipase of Pseudomonas cepacia (Amano PS) into the (3R)‐monoester (R)‐6c with an e.e. of 90%.
Facile and General Synthesis of 2‐, 3‐, or 4‐[(Dialkylamino)alkyl]pyridines and ‐piperidines
Authors: Cohen Victor I. , Jin Biyun , Reba Richard C. 
Published: July 2007

AbstractReaction of (dialkylamino)alkyl chloride with picolyllithiums provides the corresponding pyridine derivatives from which the piperidines are obtained by catalytic hydrogenation.
Simple and Condensed β‐Lactams, XVII. Monobactams Acylated with Isoxazoleacetic and Isoxazolecarboxylic Acids
Authors: Nagy József , Nyitrai József , Kajtár‐Peredy Mária 
Published: July 2007

AbstractAnalogues of aztreonam (1a) and carumonam (1b) were prepared by acylation of 3‐aminomonobactamic acid derivatives with several new and known isoxazoleacetic and isoxazolecarboxylic acid derivatives 3–10. None of the resulting new monobactams 11–18, 41a, 41b, and 54a exhibited any significant antibacterial activity.
Glycosyl Imidates, 61. – Synthesis of the Hexasaccharide Moiety of the Saponin Holotoxin A
Authors: Han Xiao‐Bing , Jiang Zi‐Hua , Schmidt Richard R. 
Published: July 2007

AbstractReaction of O‐(3‐O‐methylglucosyl) trichloroacetimidate 2a as glycosyl donor and 1,2:5,6‐di‐O‐isopropylidene‐D‐glucofuranose (3) as glycosyl acceptor furnished in the presence of TMSOTf as catalyst the β‐(1→3)‐connected disaccharide 5a. Similarly, from O‐quinovosyl trichloroacetimidate 2b and 3 the disaccharide 5b was obtained. Compound 5a was transformed via acid‐catalyzed O‐deisopropylidenation, O‐acetylation, and selective 1‐O‐deacetylation into 7. Treatment of 7 with trichloroacetonitrile in the presence of DBU furnished trichloroacetimidate 8 as glycosyl donor. Reaction of 8 with 2,4‐O‐unprotected xylopyranoside 9 as glycosyl acceptor afforded selectively trisaccharide 10. Similarly, reaction of 8 with 2,4‐O‐unprotected quinovoside 12 furnished selectively trisaccharide 13 which gave upon O‐acetylation, 1‐O‐desilylation, and then treatment with trichloroacetonitrile in the presence of DBU trichloroacetimidate 15 as triosyl donor. Reaction of 10 with 15 in the presence of TMSOTf as catalyst led to hexasaccharide 16; ensuing hydrogenolytic O‐debenzylation and then O‐acetylation afforded the desired hexasaccharide 17.