Branched-chain Sugars. XXIX. Synthesis of Moenuronic Acid (4-<i>C</i>-Methyl-<scp>d</scp>-glucuronic Acid)

Sato, Kenichi; Kubo, Kazusuke; Nie, Hong; Kodama, Hisashi; Yoshimura, Juji

doi:10.1246/bcsj.55.938

Cited by 23 publications

(6 citation statements)

References 20 publications

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“…Tertiary alcohols 5 / 6 were prepared via methyl addition (CH 3 MgI or CH 3 Li) to the known ketone 4 . The selectivity, however, was not as high as when trityl was used instead of benzyl protection of O6 (Scheme ) 2 …”

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confidence: 99%

Steric Effects Are Not the Cause of the Rate Difference in Hydrolysis of Stereoisomeric Glycosides

Jensen

Bols

2003

Org. Lett.

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[structure: see text] A long-lived and plausible explanation as to why glycosides with axial substituents are more reactive than those with equatorial substituents was given in 1955 by Edward based on sterical hindrance being relieved in the transition state. Using model compounds 5, 6, 8, and 10, we here show conclusively that sterical hindrance is not the controlling factor in glycoside hydrolysis.

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confidence: 99%

Steric Effects Are Not the Cause of the Rate Difference in Hydrolysis of Stereoisomeric Glycosides

Jensen

Bols

2003

Org. Lett.

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“…Reaction with MeMgI in Et 2 O afforded tertiary alcohol 44 with little of the epimeric alcohol, the ratio of the two being 24:1 in favor of 44 . Later in this work we would need the isomeric tertiary alcohol and it is fortunate that the stereochemical outcome of the reaction can be controlled by a proper choice of reagent (organolithium or Grignard reagent), solvent, and temperature. , In the present case, the choice of ethereal MeMgI was made by analogy with the stereochemistry reported for reaction of a related ketone differing only in the nature of the C(2) substituent (CH 2 OCPh 3 instead of C 7 H 15 ). The correctness of our stereochemical assignment was established by X-ray analysis of a compound made from 44 during our initial studies .…”

Section: Resultsmentioning

confidence: 99%

The Naturally Occurring Ketene Acetal Benesudon: Total Synthesis and Assignment of Relative and Absolute Stereochemistry

2008

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The densely functionalized ketene acetal benesudon, which is a bioactive fungal metabolite, was synthesized from D-glucose by a route involving radical cyclization to form the five-membered ring, and oxidative decarboxylation to generate the key central double bond. The originally suggested stereochemistry for the quaternary center C(5) must be revised, as both C(5) epimers were prepared and a comparison with an authentic sample was made. The absolute configuration of benesudon is 4S,5R,6S.

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“…Compound 14 was prepared 17 ) from the corresponding 4-ulose (17 g, 27 mmol) by treatment with methyllithium at -78°C, in 72% yield (12 g). #Concentration was not stated.…”

Section: Methodsmentioning

confidence: 99%

“…Compound (15) was prepared via 14 in 56% yield (2 steps) by treating the above-mentioned 4-ulose with methyllithium at -78 DC, followed by benzylation. Selective hydrolysis, followed by tosylation of 15, gave the 6-O-(p-tolylsulfonyl) derivative (17) in quantitative yield (2 steps). e) NaI, BU4NI, then DBU/DMSO, 120°C, 61 %.…”

Section: Methyl 34-bis( O-methoxymethyl)-26-bis[ O-(p-tolylsulfonylmentioning

confidence: 99%

Syntheses of Optically Active 2,3,6-Tri-O-benzyl-d-myo-inositol, Laminitol, and Mytilitol from d-Glucose

Sato¹,

Bokura²,

Taniguchi³

1994

Bulletin of the Chemical Society of Japan

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2,3,6-Tri-O-benzyl-D-myo-inositol, which is a key intermediate of D-inositol 1,4,5-triphosphate, was synthesized from D-glucose without performing any optical resolution by utilizing C2 symmetry. Laminitol and mytilitol were also synthesized from D-glucose via the same key intermediate, 1D-{1,3/2,4)-tetra-O-benzyl-2-Cmethyl-5-cyclohexene-1,2,3,4-tetrol.Since the discovery of the role of o-myo-inositol 1,4, 5-triphosphate (IP3, 1) as an intracellular second messenger for calcium mobilization,l) the biological interest in IP 3 has greatly increased. In order to explore the biochemical process, a simple, general, and efficient methodology for the chemical syntheses of 1 and its derivatives is required that will act as agonists in the phosphoinositide system. 2) The biological importance of other stereoisomers of inositol is less well established. 3 ) However, there are two known naturally-occurring Cmethyl inositols, both isolated from algae: (-)-laminitol (3) and mytilitol (4) (Chart 1). Compound 3 is especially interesting in that it has the myo-inositoltype configuration with a methyl group at C-4, and that it inhibits the growth of Neurospora crassa. 4 ) Syntheses of racemic laminitol from myo-inositol 5 ) and (-)-laminitol from toluene 6l have been reported. To date, however, for the syntheses of 1 and its derivatives, naturally occurring cyclitol derivatives, myo-inositol,7) quebrachitol,8) and quinic acid 9 ) have been mainly used as the starting materials. In general, optical resolution has been required in the case of using myo-inositol, which has a plane of symmetry. We now report on novel synthetic methods of optically active laminitol and mytilitol, as well as details concerning a communication10) about 2,3,6-tri-0-benzyl-o-myo-inositol (2) from o-glucose, respectively. (5) was prepared from o-glucose in 56% yield (3 steps) (Scheme 1). 6-Deoxyhex-5-enopyranoside derivative (6) was synthesized by the treatment of 5 with sodium iodide, tetrabutylammonium iodide, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and molecular sieves 4A in dimethyl sulfoxide (DMSO) at 90 DC (one-pot reaction, 63% yield). Detosylation of 6, followed by protection with a benzyl group, gave methyl 2-0-benzyl-6-deoxy-3,4-bis( 0-methoxymethyl)-Q-0-xylo-hex-5-enopyranoside (8) in 87% yield (2 steps). A Ferrier reaction of 8 gave a partially protected 2,3,4,5-tetrahydroxycyclohexanone derivative, which was treated with acetic anhydride in pyridine to give the corresponding enone derivative (9) in 77% yield (2 steps). The reduction of 9 with sodium tetrahydroborate--cerium (III) chloride in dichloromethane-ethanol (1: 2), followed by benzylation of the hydroxyl group gave the protected cyclohexenol derivative (10) in 89% yield (2 steps). Oxidation of 10, which has a C 2 symmetry axis, 11) with osmium tetraoxide gave a partially protected myo-inositol derivative (11) in 83% yield. The regioselective protection of the vicinal hydroxyl groups of 11 by using dibutyltin oxide and chloromethyl methyl ether, followed by benzylation of the remain...

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Branched-chain Sugars. XXIX. Synthesis of Moenuronic Acid (4-C-Methyl-d-glucuronic Acid)

Cited by 23 publications

References 20 publications

Steric Effects Are Not the Cause of the Rate Difference in Hydrolysis of Stereoisomeric Glycosides

Steric Effects Are Not the Cause of the Rate Difference in Hydrolysis of Stereoisomeric Glycosides

The Naturally Occurring Ketene Acetal Benesudon: Total Synthesis and Assignment of Relative and Absolute Stereochemistry

Syntheses of Optically Active 2,3,6-Tri-O-benzyl-d-myo-inositol, Laminitol, and Mytilitol from d-Glucose

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