No description available.

No description available.

Two organic synthetic methods for the generation of methyl bearing chiral centers have been developed using: 1) dimerization of methylketene and 2) a free radical-based addition/elimination reaction involving allyl bromides. The first method, the asymmetric dimerization of methyl ketene, followed by an asymmetric aldol reaction and the appropriate functional group manipulations enabled us to construct the (2S, 4S, 6S) trimethylnonyl subunit found in the siphonariene class of natural products. The latter method explored the stereoselective potential of a free radical-based condensation reaction by examining compounds which are known to be able to support chiral auxiliaries and chiral Lewis acids. Additionally, substituent effect on the rates of this reaction were examined closely and found to be comparable to similar, previously examined systems. The synthetic utility, magnitude and scope of this reaction are discussed. / Ph. D.

Functionalization of hydrocarbons via a free-radical based allyl transfer reaction using various allyl bromide substrates has been previously studied. The work described in this dissertation focuses on the replacement of Br by phthalimido-N-oxyl (PINO ) which helps make this chemistry environmentally friendly. To replace Br with PINO , replacement of previously used allyl-bromide substrates with new allyl-PINO substrates were necessary. Various allyl- PINO compounds were synthesized and the use of these allyl-phthalimido-N-oxyl (allyl-PINO) compounds for the functionalization of various alkyl aromatic hydrocarbons is demonstrated. Kinetic studies were performed to observe the efficiency of the new chain reaction compared to the previously reported studies with allyl-bromides. We recently discovered that these allyl substrates are useful for the functionalization of ethers and acetals. The functionalization of various cyclic and acyclic ethers was performed using these allyl transfer reactions. This reaction was also performed in-solution, which allowed us to perform these reactions at low reagent concentrations. Kinetic chain lengths were measured for these reactions. High chain lengths were observed for all used ethers. Kinetic studies to investigate the rate of radical addition-elimination processes were performed using laser flash photolysis and competition kinetics. These experiments helped us to measure the reactivity and selectivity of PINO as a chain carrier in comparison with Br. Additionally, a new competition experiment was designed to study the relative rate constant for the 􀈕-fragmentation process. For this experiment a novel substrate that contains two leaving groups, Br and PINO, was synthesized, and the relative rates of elimination of Br vs PINO were compared. / Ph. D.