Investigation of a ring fragmentation reaction for the synthesis of tethered aldehyde ynones and medium sized cyclic ynones and ynolides.

摘要

The fragmentation of gamma-silyloxy-beta-hydroxy-alpha-diazoesters to provide tethered aldehyde ynoates was discovered and developed in Prof. Brewer's laboratory. This reaction is a Lewis acid mediated heterolytic cleavage of the Cbeta-Cgamma bond of a gamma-silyloxy-beta-hydroxy-alpha-diazocarbonyl functional group array contained in a ring compound.;This dissertation describes a further study of this ring fragmentation reaction and application of this fragmentation to the preparation of synthetically useful organic molecules. The purpose of this dissertation work was three fold. The first objective was to extend this ring fragmentation reaction to the synthesis of tethered aldehyde ynones by fragmenting various gamma-silyloxy-beta-hydroxy-alpha-diazo ketone compounds. The second objective was to develop a new way to make medium size rings by fragmenting fused bicyclic gamma-silyloxy-beta-hydroxy-alpha-diazo ketones. The final goal was to use this reaction to make medium size ynolides by fragmentation of fused bicyclic gamma-silyloxy-beta-hydroxy-alpha-diazo esters to provide core structures for medium-size lactones which are synthetically challenging to make using other available methods.