Date of Award
Spring 2016
Project Type
Thesis
Program or Major
Chemistry
Degree Name
Master of Science
First Advisor
Charles K Zercher
Second Advisor
Arthur H Greenberg
Third Advisor
Christopher F Bauer
Abstract
The investigation of homologation-cyclopropanation in β-diketones revealed the involvement of two donor-acceptor cyclopropane intermediates. Cyclopropanoxide rearrangements were accomplished using reaction conditions other than zinc-carbenoid. Ring fragmentation within chain-extended tertiary cyclopropanoxides was investigated under acidic and basic reaction conditions.
Tandem chain extension-aldol reaction and lactonization were accomplished using α-carboxyester imides. A diastereomeric mixture of substituted γ-lactones (cis and trans) was isolated and characterized by NMR studies. Increased diastereomeric ratios of the trans substituted γ-lactones versus their cis counterparts were attributed towards increased syn-aldol selectivity due to chelation of the zinc-bound ester enolate with the imide carbonyl of the chiral auxiliary.
Recommended Citation
Bala, Kaushik Badri, "I. Zinc mediated homologation-cyclopropanation in beta diketones and selectivity within cyclopropanoxide rearrangements. II. Zinc mediated tandem chain extension-aldol reaction and formation of substituted gamma lactones" (2016). Master's Theses and Capstones. 1072.
https://scholars.unh.edu/thesis/1072