[2,3]-Sigmatropic rearrangements of allylic ylides and applications of homoallylic thioethers and chemical reactivity of madindoline models

This dissertation will focus on two main areas: [2,3]-sigmatropic rearrangements of allylic ylides along with further applications of homoallylic thioethers (Part I) and the chemical reactivity of madindoline models.; The first chapter reviewed [2,3]-sigmatropic rearrangements of allylic ylides. [2,3]-Sigmatropic rearrangements for allylic chloronium, bromonium, iodonium, oxonium, sulfonium, selenonium, and ammonium ylides have been precedented and were discussed. There was only one example of a [2,3]-sigmatropic rearrangement of an allylic phosphonium ylide and evidence for a concerted process was weak.; The second chapter described an investigation of a [2,3]-sigmatropic rearrangement of an allylic phosphonium ylide. Three different methods of generating unstabilized allylic phosphonium ylides were discussed. Ultimately, the [2,3] sigmatropic rearrangement of a phosphonium ylide was not realized. The major problem with this transformation resided in the inability to generate an unstabilized allylic phosphonium ylide long enough for a [2,3]-sigmatropic rearrangement to occur.; The third chapter discussed the elaboration of neopentyl alpha-silyl thioethers into aldehydes and styrenes. This method was used in the synthesis of the meroterpene natural products bakuchiol and 3-hydroxybakuchiol. Bakuchiol was evaluated for transactivation of the nuclear receptors RXRalpha, RXRbeta, RXRgamma, RARalpha, RARbeta and RARgamma. Activation results were reported.; The forth chapter discussed the directing effects of homoallylic thioethers in the hydrosilylation reaction. Homoallylic thioethers were found to accelerate the hydrosilylation of an alkene.; The final chapter discussed an investigated in the chemical reactivity of madindoline models. Madindoline natural products have been precedented to be selective inhibitors of interleukin-6 mediated cytokine cell signaling pathways. We hypothesized that madindoline was covalently bonding cysteine thiols on the extracellular domain of the receptor gp130. We tested this hypothesis by synthesizing models of madindoline and investigating their reactivity with thiols.