Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Physical Sciences and Mathematics
Novel Reactions Of Donor-Acceptor Cyclopropanes, And Diels-Alder Approach Towards Fargesine And Fumimycin, Polydoros Kyriacou
Novel Reactions Of Donor-Acceptor Cyclopropanes, And Diels-Alder Approach Towards Fargesine And Fumimycin, Polydoros Kyriacou
Electronic Thesis and Dissertation Repository
The first chapter of this thesis consists of two related projects that explore novel reactivity of donor-acceptor cyclopropanes, specifically 2-substituted cyclopropane 1,1-diesters. The first project involves the nucleophilic ring opening of donor-acceptor cyclopropanes with potassium organotrifluoroborates. It was found that during the ring opening of the cyclopropane, the diesters of the cyclopropane formed a malonyl-BF2 complex. The complex could then be hydrolyzed to afford substituted malonates. The reaction was limited to aryl cyclopropanes and potassium alkynyltrifluoroborates. The second project in this chapter explores modifying the Kerr group’s previous synthesis of tetrahydro-1,2-oxazines, such that geminal allyl, methyl esters are now …
New Chemistry Of Donor-Acceptor Cycloalkanes And Studies Towards The Synthesis Of Streptorubin B, Naresh Vemula
New Chemistry Of Donor-Acceptor Cycloalkanes And Studies Towards The Synthesis Of Streptorubin B, Naresh Vemula
Electronic Thesis and Dissertation Repository
This dissertation presents two separate chapters within the broad area of synthetic organic chemistry. The first chapter describes the annelation chemistry of donor-acceptor (DA) cyclopropanes and cyclobutanes for the synthesis of heterocycles. The Yb(OTf)3-catalyzed [4+2] cycloaddition between DA cyclobutanes and nitrosoarenes facilitated the synthesis of tetrahydro-1,2-oxazines in good to excellent yields as single diastereomers. Additionally, an unexpected deoxygenation occurred with electron-rich nitrosoarenes under MgI2-catalysis that afforded pyrrolidine products. The GaCl3-catalyzed [4+2] cycloaddition of DA cyclobutanes and cis-diazenes provided hexahydropyridazine derivatives in good to excellent yields as single diastereomers. Furthermore, a procedure to make …
Total Synthesis Of (+)-Nemorensic Acid: En Route To (-)-Callosine, Matthew R. Vriesen
Total Synthesis Of (+)-Nemorensic Acid: En Route To (-)-Callosine, Matthew R. Vriesen
Electronic Thesis and Dissertation Repository
An intramolecular oxime ether cyclopropane annulation developed in 2008 by Kerr has been shown to form 2,5-trans and 2,5-cis pyrrolidines in a stereodivergent fashion. When the oxime ether is functionalized with an enantioenhanced α-hydroxy substitutent and a leaving group, the pyrrolizidine core of (-)-callosine can be accessed in short order. Callosine is a structurally unique pyrrolizidine alkaloid isolated from Mexican flowering plant Senecio callosus. In an effort to complete the total synthesis, the total synthesis of (+)-nemorensic acid, the necic acid component of the callosine, has been established. Attempts at appending the ansa bridge via esterification and macrolactonization are discussed.