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Showing 1 to 11 of 11 for “"Nitroalkene"”.
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The Total Synthesis of (-)-Detoxinine and (+)-Casuarine Using Tandem [4 + 2]/[3 + 2] Nitroalkene Cycloadditions and Cycloadditions of Nitroethylene
… The key step is a tandem inter [4+2]/inter [3+2] nitroalkene cycloaddition involving an oxygenated nitroalkene, chiral vinyl ether, and vinyl silane dipolarophile, which establishes five of the six stereocenters present in this potent glycosidase inhibitor. The completion of the synthesis required …
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Applications of nitroalkene (4+2); cycloaddition chemistry. The asymmetric synthesis of substituted pyrrolidines and the total synthesis of mesembrine
… route for the preparation of 2,2-disubstituted 1-nitroalkenes has been developed. Conjugate 1,4-addition of zinc cuprates (RCu(CN)ZnI) to easily obtained (E)-1-nitroalkenes, followed by trapping with phenylselenenyl bromide, and subsequent oxidative elimination afforded the corresponding …
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Tandem Double Intramolecular [4+2]/[3+2] Cycloaddition of Nitro Olefins: Part I: Construction of Piperidine Rings. Part II: Construction of Vicinal Quaternary Stereogenic Centers. Part III: Progress Toward a Total Synthesis of Daphnilactone B
The fully functionalized nitroalkene intermediate for the total synthesis of daphnilactone has also been prepared and participated in the high yielding tandem double-intramolecular [4+2]/[3+2] cycloaddition to provide a mixture of two epimeric nitroso acetals. Ozonolysis of the cycloadducts, …
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Synthesis of nitrogen-containing heterocycles using nitro compounds as building blocks: Part I: Synthesis of 3-substituted azepanes. Part II: Synthesis of 1-azoniapropellanes as phase transfer catalysts
The chemistry of nitroalkenes and nitroalkanes has been explored with regard to synthesis of nitrogen-containing heterocycles, including 3-sustituted azepanes and 1-azoniapropellanes. A general synthesis of 3-sustituted azepanes has been developed using nitroalkenes as building blocks. A novel, …
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Nitroalkene (4+2) cycloadditions of achiral and chiral vinyl ethers. The stereochemical consequence of the Lewis acid promoter and studies toward the total synthesis of (+)-pretazettine
… induction in tandem inter (4+2) /intra (3+2) nitroalkene cycloadditions. Either enantiomeric series of tandem cycloaddition/hydrogenolysis product is available from the chiral auxiliary of a single absolute configuration by judicious selection of the Lewis acid promoter, …
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The total syntheses of (+)-crotanecine, (-)-hastanecine and (-)-rosmarinecine utilizing the tandem (4+2)/(3+2) cycloadditions of nitroalkenes
… promoted (4+2) cycloaddition between 2-acyloxy nitroalkene 90 and chiral vinyl ether (+)-28 afforded a nitronate which underwent facile (3+2) cycloaddition with dimethyl maleate. The resulting nitroso acetal (${-}$)-96 had all the required stereocenters for (${-}$)-hastanecine. The critical …
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Stereochemical Course of the Tandem [4+2]/[3+2] Cycloaddition of Nitroalkenes
… as MAPh) or the conformation they force upon the nitroalkene-Lewis acid complex (such as SnCl4). The s-trans vinyl ether conformation is also favored in these cases, except when phenylcyclohexanol-derived vinyl ethers are used. The s-trans conformation is then disfavored by hard, halogenated Lewis …