Strained Silacycles In Organic Synthesis : The Tandem Aldol-allylation/aldol-aldol Reaction And Their Asymmetric Variations

This thesis describes the development of tandem aldol-allylation and aldol-aldol reactions using strained silacyclic reagents developed in the laboratory of Professor James L. Leighton. A brief review of the development of the chemistry of strained silacycles is first presented followed by a study of the first tandem aldol-allylation reaction with silacyclobutane-derived reagents. This process allows the quick assembly of skipped polyol chains. An investigation with dioxacyclopentane-derived second generation of tandem reagent produced diverse polyketide units were synthesized in good to excellent yields and moderate selectivities.

A similar study of the tandem aldol-aldol reaction with strained dioxacyclopentane-derived reagents will also be presented. This highly efficient transformation could construct tetrahydropyran motif rapidly from simple aldehydes.

Chapter 5 presents our efforts to develop the asymmetric tandem reaction. Tartrate-derived chiral diol auxiliaries gave moderate enantioselectivities, and endeavors to develop an asymmetric tandem reaction continue.