Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2005. MIT Science Library copy: Issued in leaves, in a 2 v. set. Also issued in leaves, in a 2 v. set. Vita. Includes bibliographical references . I. The Development of Methods for the Iterative Synthesis of Polytetrahydropyrans An iterative method comprising chain homologation, epoxidation, 6-endo cyclization, and
... [Show full abstract] protiodesilylation was developed. Notable achievements include the development of a novel propargyl organocopper coupling method, and the complete control of stereoselectivity and regioselectivity during the iterative synthesis of a tristetrahydropyran. The synthesis of the tristetrahydropyran was achieved in 18 total operations. ... (1) homologation (2) epoxidation (3) cyclization (4) protiodesilylation ... II. The Development of a Cascade Synthesis of Polytetrahydropyrans with No Directing Groups at Ring Junctions Cascade approaches to trans-fused tetrahydropyrans were studied. After exploring acid-promoted cascade cyclizations of polyepoxysilanes and polyepoxides without directing groups, the base-promoted cascade cyclization of polyepoxysilanes was realized. In this method, as many as five operations take place in a single step to provide a tristetrahydropyran with no directing groups at any ring junctions. The synthesis of the tristetrahydropyran was accomplished in 11 steps. ... by Timothy Paul Heffron. Ph.D.
