Synthesis of (-)-Aristeromycin from D-glucose

Yoshikawa, Masayuki; Okaichi, Yoshihiko; Cheon, Bae; Kitagawa, Isao

doi:10.1016/s0040-4020(01)89060-8

Cited by 50 publications

(20 citation statements)

References 46 publications

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“…The mechanism of this transformation presumably proceeds via trialkyltin radicals forming a Sn-O bond with the nitro group. Fragmentation gives rise to Bu 3 SnONO and a (secondary or tertiary) alkyl radical 22. This transformation has been used successfully to reduce the nitro group of Diels-Alder cycloadducts 23,24.…”

Section: Introductionmentioning

confidence: 99%

Origins of Stereoselectivity in the trans Diels−Alder Paradigm

et al. 2010

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The regioselectivity and stereoselectivity aspects of the Diels-Alder/radical hydrodenitration reaction sequence leading to trans-fused ring systems have been investigated with density functional calculations. A continuum of transition structures representing Diels-Alder and hetero-Diels-Alder cycloadditions as well as a sigmatropic rearrangement have been located, and they all lie very close in energy on the potential energy surface. All three pathways are found to be important in the formation of the Diels-Alder adduct. Reported regioselectivities are reproduced by the calculations. The stereoselectivity of radical hydrodenitration of the cis-Diels-Alder adduct is found to be related to the relative conformational stabilities of bicyclic radical intermediates. Overall, the computations provide understanding of the regioselectivities and stereoselectivities of the trans-Diels-Alder paradigm.

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Section: Introductionmentioning

confidence: 99%

Origins of Stereoselectivity in the trans Diels−Alder Paradigm

et al. 2010

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“…20 One-pot selective acetonide removal and oxidative cleavage with periodic acid furnished aldehyde 55 in 98% yield, from which differentially protected sugar 56 was prepared through a known sequence of steps. 5c,21 Vorbrüggen coupling 22 with 2,6-diaminopurine then installed the base onto diacetate 56 ; however, two different products resulted, depending on the specific conditions employed.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and biological evaluation of 2′,4′- and 3′,4′-bridged nucleoside analogues

Nicolaou

Ellery

Rivas

et al. 2011

Bioorganic & Medicinal Chemistry

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Most nucleosides in solution typically exist in equilibrium between two major sugar pucker forms, N-type and S-type, but bridged nucleosides can be locked into one of these conformations depending on their specific structure. While many groups have researched these bridged nucleosides for the purpose of determining their binding affinity for antisense applications, we opted to look into the potential for biological activity within these conformationally-locked structures. A small library of 2′,4′- and 3′,4′-bridged nucleoside analogues was synthesized, including a novel 3′,4′-carbocyclic bridged system. The synthesized compounds were tested for antibacterial, antitumor, and antiviral activities, leading to the identification of nucleosides possessing such biological activities. To the best of our knowledge, these biologically active compounds represent the first example of 2′,4′-bridged nucleosides to demonstrate such properties. The most potent compound, nucleoside 33, exhibited significant antiviral activity against pseudoviruses SF162 (IC50 = 7.0 μM) and HxB2 (IC50 = 2.4 μM). These findings render bridged nucleosides as credible leads for drug discovery in the anti-HIV area of research.

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“…The choice to use 6 as starting material conducted us to invert the configuration of the carbon atom in position 3 (hydroxyl group in  position to  position) to have the D-ribose configuration as natural nucleoside. The well-established protection of 6 followed by successive oxidation, selective reduction to obtain the D-allose derivative [22], benzylation of the hydroxyl group in position 3 [23,24] and deprotection of the diol in position 5,6 [24,25] gave the D-allose derivative 7 in 51% overall yield (five steps). At this step it was notable that the oxidative cleavage followed by addition of the hex-5-ene magnesium bromide could be studied.…”

Section: Toward the Synthesis Of 3-n5′-c-cyclonucleosidesmentioning

confidence: 99%

“…Reaction conditions: (i) refs. [21][22][23][24]; (ii) 0.02 equiv Bu 2 SnO, 1.0 equiv Et 3 N, 1.0 equiv TsCl, CH 2 Cl 2 , 24 h, room temperature; (iii) 1.7 equiv K 2 CO 3 , CH 2 Cl 2 , MeOH, 0 °C for 1 h and then room temperature for 24 h; (iv) 0.1 equiv CuI, 2.7 equiv CH 2 =CHC 3 H 6 MgBr, THF, 70°C for 4 h and then room temperature for 12 h; (v) 2.5 equiv NaH, THF, room temperature for 1 h and then 0.1 equiv Bu 4 NI, 2.5 equiv BnBr, room temperature for 12 h; (vi) CH 2 Cl 2 , CF 3 COOH, H 2 O, room temperature for 18 h and then Ac 2 O, pyridine, room temperature for 12 h; (vii) 4 equiv uracile, 8 equiv BSA, CH 3 CN, reflux for 4 h and then SnCl 4 , room temperature, 12 h; (viii) 1.3 equiv K 2 CO 3 , 1.3 equiv CH 2 =CHCH 2 Br, acetone, DMF, 60 °C, 12 h. no 3-N,5′-C-cyclonucleoside was obtained using the developed strategy.…”

Section: Toward the Synthesis Of 3-n5′-c-cyclonucleosidesmentioning

confidence: 99%