Synthesis of L-Ribono- and L-Lyxono-lactone.

Kold, Henriette; Lundt, Inge; Pedersen, Christian; Andreï, Graciela; Snoeck, Robert; Balzarini, Jan; Fransson, Bengt; Ragnarsson, Ulf; Francis, George W.

doi:10.3891/acta.chem.scand.48-0675

Cited by 29 publications

(16 citation statements)

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“…[40] Treatment of 5-bromo-5-deoxy-d-ribono-1,4-lactone [41] with Bu 2 SnO and benzyl bromide did indeed afford the 2-benzylated lactone as the major product. Unfortunately, the yield never exceeded 30 % and this procedure was therefore abandoned.…”

Section: Diol 21mentioning

confidence: 99%

Synthesis of 7‐Deoxypancratistatin from Carbohydrates by the Use of Olefin Metathesis

Håkansson

Palmelund

Holm

et al. 2006

Chemistry A European J

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The stereocontrolled synthesis of (+)-7-deoxypancratistatin is described. The convergent synthesis has been achieved by two different strategies, both of which commence from a pentose and piperonal. The latter is converted into allylic bromide 7, which is then coupled with a protected methyl 5-deoxy-5-iodo-D-ribofuranoside in the presence of zinc metal. The first strategy involves a total of only 13 steps from D-ribose and piperonal, but suffers from a low yield in the zinc-mediated reaction between ribofuranoside 9, benzylamine, and bromide 7. The second strategy involves a total of 18 steps from D-xylose and piperonal. The former is converted into ribofuranoside 28, which is coupled with bromide 7 in the presence of zinc, and this is followed by ring-closing olefin metathesis. Subsequent Overman rearrangement, dihydroxylation, and deprotection then affords the natural product.

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Section: Diol 21mentioning

confidence: 99%

Synthesis of 7‐Deoxypancratistatin from Carbohydrates by the Use of Olefin Metathesis

Håkansson

Palmelund

Holm

et al. 2006

Chemistry A European J

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“…19,20 The synthesis of 24 usually employs treatment of 18 with acetone in acidic media and has been thoroughly reported in the literature, although with many variations in the reaction conditions, work up and chemical yields. 21,[25][26][27][28][29] We experienced difficulties in reproducing some of these results, and after some trial it was found that the isopropylidene lactone 24 could be produced cleanly on a multi-gram scale by first quenching the acidic reaction mixture with potassium carbonate, followed by filtering the suspension and washing the filtrate 16 giving the 5-benzoyl lactone 31 in moderate yield (Scheme 4). Milder conditions and good-to excellent yields were obtained when acetic acid was replaced by trifluoroacetic acid (TFA), 21 promoting the clean hydrolysis of the protected lactones 25-28 and 30 to the expected products 31-35.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of acylated nucleosides and ribonic-1,4-lactones as inhibitors of trypanosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH)

Sá¹,

Silveira²,

Castilho³

et al. 2002

Arkivoc

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The synthesis of a representative group of substituted nucleosides and ribonic-1,4-lactones as potential inhibitors of trypanosomal enzyme gGAPDH is described. The novel 5-acylribonic-1,4-lactones were easily obtained from ribonic lactone by a three-step procedure involving protection-deprotection protocols, in good overall yields. All compounds synthesized were subjected to inhibitory assay against gGAPDH, the most active being those carrying aromatic groups attached to the ribose ring. Other structural features responsible for the observed activities are also discussed.

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“…Synthesis and Oxidation of the N-Amino-ribonolactam 4. Treatment of the known methanesulfonate 2 [59] with neat NH 2 NH 2 ¥ H 2 O at room temperature led to the N-amino-ribonolactam 3 as the only product (Scheme 2); it was isolated by removing excess NH 2 NH 2 ¥ H 2 O and hydrazinium methanesulfonate, and silylated to yield 85% of the (tert-butyl)dimethylsilyl (TBS) ether 4. Deprotection of 3 provided 5 in a yield of 89%.…”

Section: Methodsmentioning

confidence: 99%

“…Crystal structures were analysed by the direct method (SIR 97), and non-H-atoms were refined anisotropically with SHELX-97. [59] (2.66 g, 10 mmol) in NH 2 NH 2 ¥ H 2 O (4 ml) was stirred at 238 for 6 h. The resulting clear soln. was co-evaporated with toluene (2 Â 300 ml).…”

Section: Experimental Partmentioning

confidence: 99%

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Synthesis and Oxidation of N‐Aminoglyconolactams: A Synthesis of Mannostatin A

Vasella

2004

Helvetica Chimica Acta

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The N-amino-ribono-1,5-lactam 4 was prepared in two high-yielding steps from the known methanesulfonate 2. Oxidation of 4 with t-BuOCl in the presence of 2,6-lutidine afforded the tetrazene 6 (63%). Oxidation with MnO 2 gave the deaminated lactam 7 (40%), which was also obtained, together with the lactone 8, upon oxidation of 4 with PhSeO 2 H. Oxidation with Mn(OAc) 3 /Cu(OAc) 2 provided the lactam 7 as the major and the dimer 9 as the minor product. Oxidation of 4 with 3 equiv. of Pb(OAc) 4 in toluene at room temperature gave two cyclopentanes, viz. the acetoxy epoxide 10 and the diazo ketone 11 in a combined yield of 78%. Oxidation with Pb(OBz) 4 provided 11 and the crystalline benzoyloxy epoxide 12. The crystal structure of 12 was established by X-ray analysis. The N-amino-glyconolactams 41, 46, and 51 were prepared similarly to 4. Their oxidation with Pb(OAc) 4 provided the diazo ketones 56, 57, and 58 as the only isolable products. Oxidation of the N-aminomannono-1,5-lactam 55 with Pb(OAc) 4 in the presence of DMSO gave the sulfoximine 59. Mannostatin A, a strong a-mannosidase inhibitor, was synthesized from the acetoxy epoxide 10 (obtained in 48% from 4) in seven steps and in an overall yield of 45%. . This synthesis renewed our interest in the transformation of carbohydrates into cyclopentanes. Carbohydrates indeed appear to be ideal starting materials for the synthesis of highly functionalized, enantiomerically pure cyclopentanes. The first general method for the transformation of monosaccharides to cyclopentanes is based on a fragmentation and intramolecular 1,3-dipolar cycloaddition [18]

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Synthesis of L-Ribono- and L-Lyxono-lactone.

Cited by 29 publications

References 0 publications

Synthesis of 7‐Deoxypancratistatin from Carbohydrates by the Use of Olefin Metathesis

Synthesis of 7‐Deoxypancratistatin from Carbohydrates by the Use of Olefin Metathesis

Synthesis of acylated nucleosides and ribonic-1,4-lactones as inhibitors of trypanosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH)

Synthesis and Oxidation of N‐Aminoglyconolactams: A Synthesis of Mannostatin A

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