Total Synthesis of (-)-Chokol A by an Asymmetric Domino Michael Addition-Dieckmann Cyclization
نویسندگان
چکیده
منابع مشابه
Asymmetric Synthesis of Tetrahydropyridines via an Organocatalytic One-Pot Multicomponent Michael/Aza-Henry/Cyclization Triple Domino Reaction
A low loading of a quinine-derived squaramide efficiently catalyzes the triple-domino Michael/aza-Henry/cyclization reaction between 1,3-dicarbonyl compounds, β-nitroolefins, and aldimines to provide tetrahydropyridines bearing three contiguous stereogenic centers in good yields, excellent enantiomeric excesses, and up to high diastereomeric ratios.
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An organocatalytic quadruple cascade initiated by a Friedel-Crafts-type reaction is described. The (S)-diphenylprolinol trimethylsilyl ether catalyzed reaction yields highly functionalized cyclohexenecarbaldehydes bearing a 1,1-bis[4-(dialkylamino)phenyl]ethene moiety and three contiguous stereogenic centers. The reaction tolerates various functional groups and all products are obtained with ve...
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(-)-Chokol A is a fungitoxic modified sesquiterpene isolated from the stromata of timothy grass Phleum prutense infected by the pathogenic fungus Epichloe typhinu. Isolated for the first time in 1985 by Yoshihara et al.C2I, (-)-chokol A and the more active chok01s B, CL3], D and Gl4] have recently received special attention due to their fungitoxic proper tie^[^]. So far, two syntheses for racem...
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A bifunctional squaramide catalysed aza-Michael/Michael cascade reaction between nitroalkenes and tosylaminomethyl enones or enoates has been developed. This organocatalytic cascade reaction provides easy access to highly functionalized chiral pyrrolidines with a broad substrate scope, giving the desired products in good yields (up to 99%) with good diastereoselectivities (up to 91 : 9 dr) and ...
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The stereoselective synthesis of trisubstituted 2-trifluoromethyl pyrrolidines by asymmetric Michael addition/hydrogenative cyclization is described. The direct organocatalytic addition of 1,1,1-trifluoromethylketones to nitroolefins proceeds under mild reaction conditions and low catalyst loadings to provide Michael adducts in high yield with excellent diastereo- and enantioselectivity. Cataly...
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ژورنال
عنوان ژورنال: Synlett
سال: 2006
ISSN: 0936-5214,1437-2096
DOI: 10.1055/s-2006-949653