Addition of halogenoazides to glycals

Bovin, Nicolai V.; Zurabyan, S. E.; Khorlin, A. Ya.

doi:10.1016/s0008-6215(00)87138-4

Cited by 83 publications

(26 citation statements)

References 13 publications

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“…When perbenzylated glycals 16 (12) and 2b (13) were reacted under the same conditions, perbenzylated phenyl 2-azido-2-deoxy-I-seleno-a-d-glycopyranosides were obtained in low yield, in agreement with recent results (14). This could be due to oxidative cleavage of the benzyl group under reaction conditions.…”

Section: Resultssupporting

confidence: 91%

Preparation of diversely protected 2-azido-2-deoxyglycopyranoses from glycals

Czernecki¹,

Ayadi²

1995

Can. J. Chem.

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A new and efficient preparation of diversely protected 2-azido-2-deoxyglycopyranosides from the corresponding glycals is described. The glycals are first transformed into protected phenyl 2-azido-2-deoxyselenoglycopyranosides by azido-phenylselenylation. Two procedures were employed according to the protecting groups present: sodium azide and diphenyldiselenide in the presence of (diacetoxyiodo)benzene for peracetylated glycals (Procedure A) or trimethylsilyl azide and tetra-n-butylammonium fluoride in the presence of N-phenylselenophthalimide for perbenzylated glycals (Procedure B). A gluco-manno mixture (90%) is obtained from protected d-glucal whereas only the galacto isomer is formed from protected d-galactal(75%). The compatibility of the second procedure with one free hydroxyl group and a variety of protecting groups was verified with 1,5-anhydro-2-deoxy-3,4-O-isopropylidene-d-lyxo-hex-l -enitol and its 6-0-acety I, 6-0-allyl, 6-0-benzyl, and 6-0-tert-butyldimethylsilyl derivatives as well as with 1,s-anhydro-4,6-0-benzylidene-2-deoxy-d-lyxohex-1-enitol and its 3-0-acetyl and 3-0-benzyl derivatives, which were transformed into phenyl2-azido-2-deoxy-a-d-selenogalactopyranoside derivatives in good yield. In the second step, hydrolysis of these selenoglycosi&s afforded diversely protected glycopyranoses in high yield. Peracetylated derivatives were hydrolyzed in the presence of N-iodosuccinimide, whereas mercury trifluoroacetate was employed for 3,4-0-isopropylidene, 4,6-0-benzylidene, and perbenzylated derivatives. In some cases the two steps can be canied out without isolation of the intermediate selenoglycoside.Key words: glycals, 2-azido-2-deoxygalactopyranose, 2-azido-2-deoxyglucopyranose, selenoglycosides.RCsumC : On dCcrit une nouvelle prCparation efficace de divers 2-azido-2-dCsoxyglycopyranosides protCgCs de diverses manikres 8 partir des glycals correspondants. Dans la premikre Ctape, on transforme les glycals en 2-azido-2-dCsoxysCICnoglycopyranosides de phenyle protCgCs par azidophCnylsClCnylation. On a utilisC deux mCthodes suivant la nature des groupes protecteurs presents : azoture de sodium et diphCnyldisClCnure en prCsence de (diac6toxyiodo)benzkne avec les glycals peracCtylCs (rnCthode A) ou azoture de trimCthylsilyle et fluorure de tCtra-n-butylammonium en prCsence de N-phCnylsC1Cnophtalimide avec les glycals perbenzylCs (mCthode B). On obtient un mClange gluco-manno (90%) 8 partir du d-glucal alors que l'on obtient uniquement l'isornkre galacto 8 partir du d-galactal(75%). Utilisant le 1,5-anhydro-2-dCsoxy-3,4-O-isopropylidkne-d-lyxohex-1-Cnitol et ses dCrivCs ainsi que le 1,sanhydro-4,6-O-benzylidkne-2-dCsoxy-d-lyo-hex-l-Cnitol et ses derives 3-0-acCtyl-et 3-0-benzyl-qui ont CtC transformis en dCrivCs du 2-azido-2-dCsoxy-a-galactopyranoside de phCnyle avec de bons rendements, on a vCrifiC la compatibilitk de la deuxikme mCthode avec la prtsence d'un groupe hydroxyle libre et de divers groupes protecteurs. Dans la deuxikme Ctape, l'hydrolyse de ces sClCnoglycosides fournit divers ...

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Section: Resultssupporting

confidence: 91%

Preparation of diversely protected 2-azido-2-deoxyglycopyranoses from glycals

Czernecki¹,

Ayadi²

1995

Can. J. Chem.

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“…2 However, reaction of sugar 2-enes with BrN 3 in the presence of Dibenzoyl Peroxide (radical reaction) led, after treatment with Mercury(II) Acetate, to formation of 2-acetoxy-3-azido sugars. 10 Aromatic or other substituents on a double bond, which can stabilize a positive charge well, can lead to a mixture of stereoisomers. 2b In polar nucleophilic solvents (MeCN, DMF, HOAc, MeOH), reaction of BrN 3 with alkenes leads to solvent participation (eq 3).…”

Section: Phmentioning

confidence: 99%

Bromine Azide

Häßner¹

2001

Encyclopedia of Reagents for Organic Synthesis

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“…and 2-Azido-3,4,6-tri-0-benzyl-2-deoxy-a-o-mannopyranosyl Nitrate (19). Azidonitration of 2 g (4.8 mmol) of 16 [32] [33] …”

Section: 46-tri-o-acetyl-2-azido-2-deoxy-a-and -P-o-glucopyranosvlmentioning

confidence: 99%

Glycosylphosphonates of 2‐Amino‐2‐deoxy‐aldoses. Synthesis of a Phosphonate Analogue of Lipid X

Briner¹,

Vasella²

1987

Helvetica Chimica Acta

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A preparation of glycosylphosphonates (27,28,36,38, and 39) from 2-azido-2-deoxy-glycoses (26,35, and 37) and the synthesis of the non-isosteric phosphonate analogue 3a of lipid X (2) are described. The 2-azido group was introduced by azidonitration. Treatment of the 1-0-acetyl-2-azido-2-deoxy-~-~-galactopyranose 22 with 1.5-3 equiv. of P(OMe), and 1.2-2.5 equiv. of TfOSiMe, gave mainly recovered starting material. In P(OMe), as the solvent, the dimethyl phosphoramidate 24 was obtained by way of a Staudinger reaction, even in the presence of TfOSiMe,. Treatment of the benzylated a-D-galacto-trichloroacetimidate 26, however, with P(OMe), and TfOSiMe, gave a 1 : I mixture of the a-and p-D-galacto-phosphondtes 27 and 28, while the acetylated a -D -g h C Oimidate 35 led to the a-D-glUC0-contigurated phosphonate 36. The stereoselectivity of the phosphonate formation is related to the relative ease of formation of oxonium-ion intermediates from 26 and 35. Starting from the phosphonate 36, deacetylation, benzylidenation, reduction of the azido group, acylation with (R)-3-(benzy1oxy)tetradecanoic acid and deprotection yielded the desired compound 3a which was crystallized in the presence of 2 equiv. of (aminomethylidyne)trimethanol (Tris). The structure of the phosphonates was deduced from their 'H-, I3C-, and ,'P-NMR spectra.

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Addition of halogenoazides to glycals

Cited by 83 publications

References 13 publications

Preparation of diversely protected 2-azido-2-deoxyglycopyranoses from glycals

Preparation of diversely protected 2-azido-2-deoxyglycopyranoses from glycals

Bromine Azide

Glycosylphosphonates of 2‐Amino‐2‐deoxy‐aldoses. Synthesis of a Phosphonate Analogue of Lipid X

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