Synthesis of methylene bridged C-disaccharides

Giese, Bernd; Hoch, Monika; Lamberth, Clemens; Schmidt, Richard R.

doi:10.1016/s0040-4039(00)80300-7

Cited by 93 publications

(10 citation statements)

References 18 publications

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“…These epimers were readly separated and the gluco isomers 4a,b were converted into iodo derivatives 5a,b by using triphenylphosphine/iodine.ll The gafacto isomers 4a',b' can be also transformed into 4a,b via oxidation, isomerisation, and then reduction, as previously reported. 5 The required open-chain Cg-elecnophile 8 (Scheme 2) was readily obtained from 2,3,4,6-tetra-0-benzyl-~-glucose diethyldithioacetal (6).20 Reaction of 6 with terr-butyldimethylchlorosilane (TBDMS-Cl) in the presence of imidazole afforded 5-0-silyl protected 7 which was transformed into 8 by treatment with HgC12/CdC03 in an acetonewater mixture.…”

Section: Resultsmentioning

confidence: 99%

Synthesis ofC-Disaccharides An Unusual Ring Closure Reaction

Khan

Sharma

Schmidt

1995

Journal of Carbohydrate Chemistry

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Reaction of the 4-C-lithiomethyl intermediates, obtained from 4-deoxy-4-Ciodomethylglucopyranosides 5a,b, with open-chain glucose derivative 8 afforded 4-deoxy-4-C-heptitylglucopyranosides 9a,b. Mesylation of the newly generated hydroxy group and then desilylation gave lla,b which were subjected to ring closure under basic conditions. Surprisingly, no C-bridged cellobiosides 12a,b (or, alternatively the corresponding maltosides) were obtained as major products; with loss of one benzyl alcohol residue the furanosides 13a,b were preferentially formed. Their generation and structural assignment is discussed.

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Section: Resultsmentioning

confidence: 99%

Synthesis ofC-Disaccharides An Unusual Ring Closure Reaction

Khan

Sharma

Schmidt

1995

Journal of Carbohydrate Chemistry

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“…The first example was disclosed by Schmidt and co-workers as early as 1988 (Scheme 42). [52] Oxidation of the pyranosides 207 and subsequent treatment of the obtained glycopyranosyl phenylsulfoxides 208 with lithium diisopropylamide (twofold excess) and formaldehyde afforded the 2-(hydroxymethyl) derivatives 210. Under acidic conditions at elevated temperature these compounds underwent conversion into the optically active α-methylene δ-lactones 211a or 211b.…”

Section: Application Of Sugar Derivatives In the Synthesis Of Polyhydmentioning

confidence: 99%

Recent Advances in the Synthesis of α‐Alkylidene‐Substituted δ‐Lactones, γ‐Lactams and δ‐Lactams

2011

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α-Alkylidene-substituted δ-lactones and corresponding γ-and δ-lactams constitute important classes of natural compounds that display diverse biological activities. This review gives a brief description of the occurrence and biological activities of the title compounds and then summarizes the methods available for their preparation. Attention is given mainly to the synthetic approaches developed during the last decade, including those from our own research group. The latest developments in the synthesis of nonracemic α-alkylidene-substituted δ-lactones, γ-lactams and δ-lactams are also discussed.

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“…Early on, Giese et al applied this strategy to the synthesis of methylene bridged C-disaccharides [151]. In their work, reaction of the lactone 16 with 2,3,4,6-tetra-O-acetyl-D-mannopyranosyl bromide gave a 1/1 mixture of the desired compound (Scheme 30).…”

Section: Coupling Between a Radical Anomeric Carbon And An Unsaturatementioning

confidence: 99%