An improved method for the synthesis of anhydroalditols

Jeffery, A.; Nair, Vasu

doi:10.1016/0040-4039(95)00618-m

Cited by 26 publications

(5 citation statements)

References 23 publications

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“…Evaporation of the solvent and flash chromatography (hexane/ether 1:1) gave the desired alcohol 11b as a clear oil (13.8 mg, 44%). The spectral data for this compound were consistent with the literature data 10b…”

Section: Methodssupporting

confidence: 88%

Synthesis of Methylene-Expanded 2‘,3‘-Dideoxyribonucleosides

Jung

Kiankarimi

1998

J. Org. Chem.

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A method for the preparation of methylene-expanded 2‘,3‘-dideoxyribonucleosides is reported. The very inexpensive starting material levoglucosenone 8 was converted into the known mixture of alcohols 12ab which were converted into the required silyl ether alcohol 26 in six steps via either of two routes. The first involved a one-step acetylation and opening of the anhydro sugar bridge to give the triacetates 20ab which were reduced with triethylsilane and silyl triflate to afford the diacetates 21ab, both of which gave 26 after further functional group conversions. The second route entailed a simple acetylation of 12ab followed by reduction with triethylsilane and silyl triflate to give the monoacetates 19ab, both converted via straightforward chemistry into 26. Mesylation of the alcohol of 26 furnished the mesylate 27. Alkylation of adenine with the mesylate 27 afforded the silyl ether 28 which was deprotected to give the desired modified dideoxy nucleoside 7a. Alkylation of 2,6-diaminopurine 38 with the mesylate gave the protected diaminopurine nucleoside 39. Upon acetylation, it produced a mixture of di- and monoacetates 40 − 41, the latter of which was transformed into the desired guanosine analogue 7e. Thus, two new nucleoside analogues 7ae were prepared from levoglucosenone 8.

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Section: Methodssupporting

confidence: 88%

Synthesis of Methylene-Expanded 2‘,3‘-Dideoxyribonucleosides

Jung

Kiankarimi

1998

J. Org. Chem.

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“…The dihydroxylation reactions proceeded with an excellent trans selectivity with respect to the substituent at the C-3 carbon atom. The obtained products were benzoylated with benzoyl chloride/pyridine in the presence of DMAP to give the fully benzoylated isoxazolidine-4,5-diols 6a and 6b, which were subsequently treated with Et 3 SiH (3 equiv) and TMSOTf (2 equiv) in anhydrous CH 2 Cl 2 at room temperature for 2 h [28]. To our delight, already the first attempts afforded the isoxazolidines 7a and 7b in very good 74% and 80% yield, respectively.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of 3-substituted isoxazolidin-4-ols using hydroboration–oxidation reactions of 4,5-unsubstituted 2,3-dihydroisoxazoles

Dikošová

Laceková

Zaborsky

et al. 2020

Beilstein J. Org. Chem.

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Isoxazolidines represent a very important class of N/O-containing heterocycles used as the key intermediates in the synthesis of more complex cyclic and acyclic compounds, including various biologically active molecules. Here, we present a fast and highly stereoselective approach towards both C-3/4-cis and C-3/4-trans isomers of 3-substituted isoxazolidin-4-ols. The strategy relies on a highly regio- and trans-stereoselective hydroboration–oxidation reaction of the 4,5-unsubstituted 2,3-dihydroisoxazoles with basic hydrogen peroxide. The consecutive oxidation/reduction route, sequentially employing Dess–Martin periodinane and ʟ-selectride, is used for the inversion of the C-3/4-trans relative configuration of the isoxazolidine ring. The significance of the method lies in its variability and applicability to a concise synthesis of various 4-hydroxyisoxazolidines, starting from the readily available C-alkyl/aryl-nitrones. The resemblance to 3-hydroxypyrrolidines certainly makes the 4-hydroxyisoxazolidines important and valuable structural fragments in drug discovery.

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“…[31][32][33] The anhydrogalactitol derivative was then synthesized as follows. A deoxygenation reaction was carried out by reductive deacetylation using trimethylsilyl (TMS) triflate and triethylsilane at room temperature, as described for the synthesis of anhydroalditols, 34 to produce the 1,4-anhydro-4-thiogalactitol compound 7, in 63% yield. The presence of the adjacent acetate group at C-2 presumably facilitates the deoxygenation process by stabilizing the thiacarbenium ion intermediate.…”

Section: Resultsmentioning

confidence: 99%