Investigations of transition state geometry in the intramolecular aldol reaction and the intramolecular reaction of allylsilanes with aldehydes

Investigations into factors which influence the transition state geometry of the aldol reaction are described. Synthesis of two bicyclic model systems designed to study base-catalyzed intramolecular aldol reactions are reported, along with the effects that various metal counterions, solvents, and additives have on the stereochemical course of cyclization in these models. These models are the first to provide data concerning the factors which influence the preference for an open versus closed transition state in the absence of extraneous steric bias. Results indicate that coordination ability of the metal counterion is a major factor in influencing transition state geometry. In addition, synthesis of two model systems designed to study Lewis acid-catalyzed reactions of enolsilanes with acetals are described. The influence of change in Lewis acid and solvent on the stereochemical course of reaction are reported. Cyclizations in these model systems are highly selective and relatively insensitive to the Lewis acid and are interpreted in terms of reaction through an S$\sb{\rm N}$2 mechanism, with a possible change in mechanism when $\rm BF\sb3{\cdot}Et\sb2 O$ is used.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Henke, Brad Richard

Contributors dc:contributor

• Deuman, Scott E.

• Chemistry, Organic

Statement dc:rights

• Copyright 1989 Henke, Brad Richard

Language dc:language

eng

Identifier

AAI9010880
(UMI)AAI9010880

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/21519