Synthesis of Protected Carbohydrate Derivatives Through Homologation of Threose and Erythrose Derivatives with Chiral .gamma.-Alkoxy Allylic Stannanes

Marshall, James A.; Seletsky, Boris M.; Luke, George P.

doi:10.1021/jo00091a034

Cited by 54 publications

(30 citation statements)

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“…l-Idose 30 [57] was treated with MeOH under acidic conditions to give methyl l-idosides 31 and 32 (31/32 2.2:1). Oxidation of the b-anomer 31 [58] with chromium trioxide/H 2 SO 4 (Jones reagent), followed by esterification of the intermediate acid provided methyl uronate 34 [59,60] in 72 % yield. Finally, 34 was hydrogenolyzed with Pd(OH) 2 /C to give unprotected methyl uronate 35.…”

Section: Resultsmentioning

confidence: 99%

Divergent Synthesis of L‐Sugars and L‐Iminosugars from D‐Sugars

Takahashi

Shida

Hitomi

et al. 2006

Chemistry A European J

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An efficient divergent synthesis of L-sugars and L-iminosugars from D-sugars is described. The important intermediate, delta-hydroxyalkoxamate, prepared from D-glucono-/galactono-1,5-lactone, was cyclized under Mitsunobu conditions to give the O-cyclized oxime compound and the N-cyclized lactam compound as mixtures. A more detailed investigation revealed that the appropriate protecting groups and solvents controlled the specificity for the O-/N-cyclization of the delta-hydroxyalkoxamate. Suitable protection at the 6-position of delta-hydroxyalkoxamate, derived from D-glucono-1,5-lactone, afforded the corresponding O-alkylation product alone. Thus we succeeded in applying this to the total synthesis of L-iduronic acid. In contrast, with both TBDMS as the protecting group and RCN as the solvent the efficient conversion of D-glucono/galactono-1,5-lactone into the corresponding L-iminosugars (L-idonolactam and L-altronolactam) was achieved.

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Section: Resultsmentioning

confidence: 99%

Divergent Synthesis of L‐Sugars and L‐Iminosugars from D‐Sugars

Takahashi

Shida

Hitomi

et al. 2006

Chemistry A European J

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“…32–37, 44, 45 Indeed, when diol 6 was reacted with Ag 2 O (1.6 equiv) and MeI (4.6 equiv) in DMF at ambient temperature for 48 hours (Scheme 4), bisether 9a was isolated in good yield (67%). 33 Saponification of diester 9a gave the required bisether diacid ( 12a ) in 73% yield (Scheme 4).…”

Section: Resultsmentioning

confidence: 99%

Synthesis of norbornane bisether antibiotics via silver-mediated alkylation

et al. 2015

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A small series of norbornane bisether diguanidines have been synthesized and evaluated as antibacterial agents. The key transformation—bisalkylation of norbornane diol 6—was not successful using Williamson methodology but has been accomplished using Ag2O mediated alkylation. Further functionalization to incorporate two guanidinium groups gave rise to a series of structurally rigid cationic amphiphiles; several of which (16d, 16g and 16h) exhibited antibiotic activity. For example, compound 16d was active against a broad range of bacteria including Pseudomonas aeruginosa (MIC = 8 µg/mL), Escherichia coli (MIC = 8 µg/mL) and methicillin-resistant Staphylococcus aureus (MIC = 8 µg/mL).

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“…Methyl ketone 79 was next prepared in five steps (Scheme 23B). Reduction of known lactone (+)- 81 67 with DIBAL-H followed by exposure of the resulting lactol to TMSCHN 2 /LDA 68 provided alkynyl alcohol (+)- 82 in good overall yield (85%, 2 steps). Parikh-Doering oxidation 58 was then followed by methylation of the resulting aldehyde with AlMe 3 ; a second Parikh-Doering oxidation led to the corresponding methyl ketone, albeit with partial racemization at the α-stereogenic center during the methylation.…”

Section: Resultsmentioning

confidence: 99%

(+)-Sorangicin A: evolution of a viable synthetic strategy

et al. 2011

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An effective, asymmetric total synthesis of the antibiotic (+)-sorangicin A (1) has been achieved. Central to this venture was the development of first and second generation syntheses of the signature dioxabicyclo[3.2.1]octane core, the first featuring chemo- and stereoselective epoxide ring openings facilitated by a Co2(CO)6-alkyne complex, the second involving a KHMDS-promoted epoxide ring formation/opening cascade. Additional highlights include effective construction of the dihydro- and tetrahydropyran ring systems, respectively via a stereoselective conjugate addition/α-oxygenation protocol and a thioketalization/hydrostannane reduction sequence. Late-stage achievements entailed two Julia–Kociénski olefinations to unite three advanced fragments with high E-stereoselectivity, followed by a modified Stille protocol to introduce the Z,Z,E trienoate moiety, thereby completing the carbon skeleton. Mukaiyama macrolactonization, followed by carefully orchestrated Lewis and protic acid-promoted deprotections that suppressed isomerization and/or destruction of the sensitive (Z,Z,E)-trienoate linkage completed the first, and to date only, total synthesis of (+)-sorangicin A (1)

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Synthesis of Protected Carbohydrate Derivatives Through Homologation of Threose and Erythrose Derivatives with Chiral .gamma.-Alkoxy Allylic Stannanes

Cited by 54 publications

References 0 publications

Divergent Synthesis of L‐Sugars and L‐Iminosugars from D‐Sugars

Divergent Synthesis of L‐Sugars and L‐Iminosugars from D‐Sugars

Synthesis of norbornane bisether antibiotics via silver-mediated alkylation

(+)-Sorangicin A: evolution of a viable synthetic strategy

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