1,058 research outputs found

    Recent progress in the synthesis of six-membered aminocyclitols (2008-2017)

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    Aminocyclitols are of interest as glucosidase inhibitors, as probes for the study of pseudoglycosyltransferases, and as potential therapeutics for the treatment of Gaucher’s disease. The synthesis of these targets was reviewed in early 2008, and the aim of this review is to cover material relevant to the synthesis of aminocyclitols since that time. While not a focus of this review, biological evaluation of compounds will be presented where it is recorded in the literature

    Nucleophilic Addition to (3-Methylpentadienyl)iron(1+) Cations: Counterion Control of Regioselectivity; Application to the Enantioselective Synthesis of 4,5-Disubstituted Cyclohexenones

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    The regioselectivity of malonate addition to (3-methylpentadienyl)Fe(CO)3+ is controlled by the malonate−counterion association. The Li+ salt of malonate proceeds via C1 nucleophilic attack to afford the 1,3Z-diene complex 4a, while reaction of highly dissociated ion pair (i.e., Na+ or Li+/12-crown-4) salt proceeds at the C2 internal carbon to eventually afford cyclohexenone products 6. Reaction of 1a with the sodium salt of bis(8-phenylmenthyl)malonate proceeds with excellent diastereocontrol to afford a single diastereomeric cyclohexenone

    Synthetic Studies Directed Toward Streptenol D: Enantioselective Preparation of the 3,5-diacetoxy-6\u3cem\u3eE\u3c/em\u3e,8\u3cem\u3eE\u3c/em\u3e-decadiene Segment

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    The enantioselective preparation of 2-(3′R,5′R-diacetoxy-6E,8E-decadienyl)-1,3-dioxane, (+)-13, is described. This synthesis of the skeleton of streptenol D utilizes the ability of a diene-complexed (tricarbonyl)iron unit to serve as a protecting and stereodirecting functionality

    Chemistry and Biology of Streptogramin A Antibiotics

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    The streptogramin A antibiotics have proven to be highly active against Gram positive bacteria, particularly methicillin-resistant Staphylococcus aureus. Members of this group of compounds are characterized by a 23-membered macrocycles containing polyene, oxazole, amide and ester functionality. The chemistry and biology of these valuable antimicrobial agents is covered

    Studies on the Preparation of Protomycinolide IV: Enantioselective Synthesis of the C3–C9 Segment

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    The C3–C9 segment, (−)-16, of the polyene macrolide antibiotic protomycinolide IV (1a) was prepared in optically pure form from commercially available methyl (S)-2-methyl-3-hydroxypropionate in 12 steps giving 17% yield

    Recent Applications of the Simple Hydrocarbon Cyclooctatetrene as a Starting Material for Complex Molecule Synthesis

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    Cyclooctatetraene [COT], a simple non-aromatic cyclic polyene, is capable of undergoing a variety of oxidation and cycloaddition reactions to afford polycyclic structures. In addition, complexation of COT or the cycloaddition products with transition metals facilitates bond formation. Recent developments in the reactivity of COT and application to the synthesis of naturally occurring and non-naturally occurring compounds is reviewed

    Synthesis of cyclopropanes via organoiron methodology: stereoselective preparation of cis-2-(2’-carboxycyclopropyl)glycine

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    A stereoselective route to cis-2-(2′-carboxycyclopropyl)glycine has been developed. exo-Nucleophilic addition to the (bicyclo[5.1.0]octadienyl)iron(1+) cation establishes the relative stereochemistry at the cyclopropane ring and the α-stereocenter. Subsequent removal of the metal and cleavage of the cyclic diene gave the protected target 10, which upon hydrolysis gave 1. A stereoselective route to cis-2-(2′-carboxycyclopropyl)glycine has been developed. exo-Nucleophilic addition to the (bicyclo[5.1.0]octadienyl)iron(1+) cation establishes the relative stereochemistry at the cyclopropane ring and the α-stereocenter
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