A novel transformation of four aldoses to some optically pure pseudohexopyranoses and a pseudopentofuranose, carbocyclic analogs of hexopyranoses and pentofuranose. Synthesis of derivatives of (1S,2S,3R,4S,5S)-, (1S,2S,3R,4R,5S)-, (1R,2R,3R,4R,5S)-, (1S,2S,3R,4S,5R)-2,3,4,5-tetrahydroxy-1-(hydroxymethyl)cyclohexanes and (1S,2S,3S,4S)-2,3,4-trihydroxy-1(hydroxymethyl)cyclopentane

Tadano, Kin‐ichi; Maeda, Hiroo; Hoshino, M.; Iimura, Youichi; Suami, Tetsuo

doi:10.1021/jo00386a011

Cited by 58 publications

(12 citation statements)

References 3 publications

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“…Model D was chosen for the study of the spectroscopic characteristics of the C.11−C.15 portion of MTX. Scheme 3 outlines the synthesis of the C.13−C.19 portion from the aldehyde 18 , readily available from d -ribose. Addition of the allyl group was best achieved by the reaction of allylindium bromide with 18 to yield a 6:1 mixture of the two possible diastereomers.…”

Section: Relative Stereochemistrymentioning

confidence: 99%

Complete Relative Stereochemistry of Maitotoxin

et al. 1996

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By addressing the relative stereochemistry of the four acyclic portions via organic synthesis, the complete relative stereochemistry of maitotoxin (MTX) has been established as 1B. The relative stereochemistry of the C.1−C.15 portion was elucidated via a two-phase approach: (1) the synthesis of the eight diastereomers possible for model C, representing the C.1−C.11 portion, and the eight diastereomers possible for model D, representing the C.11−C.15 portion, and the comparison of their proton and carbon NMR characteristics with those of MTX, concluding that 9 and 35 represent the relative stereochemistry of the corresponding portions of MTX; (2) the synthesis of the two remote diastereomers 51 and 52, and comparison of their proton and carbon NMR characteristics with those of MTX, concluding that 51 represents the relative stereochemistry of the C.1−C.15 portion of MTX. The relative stereochemistry of the C.35−C.39, C.63−C.68, and C.134−C.142 acyclic portions was established via (1) the synthesis of the 8, 8, and 16 diastereomers possible for models E, F, and G, respectively, and (2) the comparison of their proton and carbon NMR characteristics with those of MTX, concluding that 81, 117, and 187, respectively, represent the relative stereochemistry of the corresponding portions of MTX. Some biogenetic considerations have been given to speculate on the absolute configuration of MTX. The vicinal proton coupling constants observed for models 51, 81, 117, and 187 were used to elucidate their preferred solution conformation. Assembling the preferred solution conformations found for the four acyclic portions allows one to suggest that the approximate global conformation of MTX is represented by the shape of a hook, with the C.35−C.39 portion being its curvature. MTX appears to be conformationally relatively rigid, except for conformational flexibility around the C.7−C.9 and C.12−C.14 portions. On the basis of the experimental results gained in the current work, coupled with those in the AAL-toxin/fumonisin area, it has been pointed out that the structural properties of 51, 81, 117, 187 and their diastereomers are inherent to the specific stereochemical arrangement of the small substituents on the carbon backbone and are independent from the rest of the molecule. Thus, it has been suggested that each of these diastereomers has the capacity to install a unique structural characteristic through a specific stereochemical arrangement of substituents on the carbon backbone, and that fatty acids and related classes of compounds may be able to carry specific information and serve as functional materials in addition to structural materials.

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Section: Relative Stereochemistrymentioning

confidence: 99%

Complete Relative Stereochemistry of Maitotoxin

et al. 1996

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“…L ‐Arabinose ( 5 ) was converted into the diethyldithioacetal 6 9,10 and the hydroxy groups were then specifically protected to give 7 11 (Scheme ). The aldehyde 8 , regenerated by treatment with NBS12 in the presence of 2,6‐lutidine, was condensed with two different glyoxals and with cyclohexane‐1,2‐dione to give the linear imidazolo sugars 9 – 11 , according to the method of Rothenberg 13.…”

Section: Resultsmentioning

confidence: 99%

“…126–127 °C. Foam: [α] D 20 = +30 ( c = 3.3, CHCl 3 ); enantiomer:11 [α] D 20 = –29.8 ( c = 1.06, CHCl 3 ); crystals: [α] D 20 = +11 ( c = 1.1, MeOH). 1 H NMR (400 MHz, CDCl 3 ): δ = 1.17 (t, 3 H, C H 3 CH 2 S), 1.19 (t, 3 H, 3 H, C H 3 CH 2 S), 2.49–2.71 (m, 4 H, CH 3 C H 2 S), 3.08 (br.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of Substituted Imidazolo[1,2‐a]piperidinoses and Their Evaluation as Glycosidase Inhibitors

et al. 2006

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The synthesis of substituted imidazolo[1,2‐a]‐L‐arabino‐piperidinoses is reported. The substituents are methyl, phenylmethyl, phenylethyl, cyclohexylethyl, pyridinylethyl, piperidinylethyl, phenylpropyl and hydroxymethyl. All substituents are connected to the imidazole moiety. Examination of the inhibitory properties of the newly synthesised compounds against a β‐glucosidase (from almonds) and a β‐galactosidase (from Escherichia coli) lead to the conclusion that the substitution of the C‐2 position on the imidazole moiety with cyclohexylethyl or phenylethyl gives the best results (Ki = 2 and 4 nM, respectively, against a β‐galactosidase) as compared with the non‐substituted azasugar. The synthesis of the imidazolo[1,2‐a]‐D‐xylo‐piperidinose substituted with phenylethyl is also reported, as well as its inhibitory potency against the β‐xylosidase from Aspergillus niger.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

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“…Later on, the same authors prepared (+)-methyl 3,4,5- O -tribenzyl-4- epi -shikimate from l -arabinose in a similar manner . In a modified procedure, the two C–C bond formation was achieved in a two-step protocol, which allowed also the synthesis of (−)-methyl 3,4,5- O -tribenzyl-5- epi -shikimate from d -ribose.…”

Section: Synthesis Of Shikimic Acidmentioning

confidence: 99%

Production and Synthetic Modifications of Shikimic Acid

2018

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Shikimic acid is a natural product of industrial importance utilized as a precursor of the antiviral Tamiflu. It is nowadays produced in multihundred ton amounts from the extraction of star anise (Illicium verum) or by fermentation processes. Apart from the production of Tamiflu, shikimic acid has gathered particular notoriety as its useful carbon backbone and inherent chirality provide extensive use as a versatile chiral precursor in organic synthesis. This review provides an overview of the main synthetic and microbial methods for production of shikimic acid and highlights selected methods for isolation from available plant sources. Furthermore, we have attempted to demonstrate the synthetic utility of shikimic acid by covering the most important synthetic modifications and related applications, namely, synthesis of Tamiflu and derivatives, synthetic manipulations of the main functional groups, and its use as biorenewable material and in total synthesis. Given its rich chemistry and availability, shikimic acid is undoubtedly a promising platform molecule for further exploration. Therefore, in the end, we outline some challenges and promising future directions.

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Cited by 58 publications

References 3 publications

Complete Relative Stereochemistry of Maitotoxin

Complete Relative Stereochemistry of Maitotoxin

Synthesis of Substituted Imidazolo[1,2‐a]piperidinoses and Their Evaluation as Glycosidase Inhibitors

Production and Synthetic Modifications of Shikimic Acid

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