Master of Science (MS)
Semester of Degree Completion
T. Howard Black
Thesis Committee Member
Jerry W. Ellis
Two-carbon ring expansions of vinyl β-lactones, were carried out by Lewis acids (BF3-Et2O or Et2AlCl) via an ionization/cation rearrangement. β,γ-unsaturated δ-lactones were produced as efficient protocols for the synthesis of bioactive substances.
Vinyl β-lactones were prepared via ring closure of corresponding unsaturated β-hydroxy acids. Differently structured substrates were examined to study the influence of the substituents on the rearrangement. Other factors, such as temperature, solvent and catalyst were also studied in search of suitable reaction conditions.
This method is moderately successful in providing fused-ring δ-lactones, but higher yields (so far total yield of 24.8%) and a better method for the separation of β- and δ-lactones are required for useful synthetic applications.
The successful implementation of this conceptually novel strategy will provide a versatile and expedient route for the synthesis of δ-lactones bearing a wide range of substitution patterns.
Xiong, Li, "An Expeditious Synthesis of β,γ-Unsaturated δ-Lactones: Useful Pharmacological Synthetic Intermediates" (1997). Masters Theses. 1799.