The intramolecular nucleophile catalyzed aldol-lactonization (NCAL) process
was optimized successfully. A variety of C9-acylated cinchona alkaloids were
synthesized and used for NCAL reactions with non-activated aldehydes. New
pyridinium salts, derivatives of MukaiyamaÂs reagent, led to marked improvements in
efficiency for the catalytic, asymmetric NCAL process while maintaining high
enantioselectivity. Larger scale versions of the catalytic, asymmetric NCAL reaction
were also developed allowing practical access to chiral bicyclic b-lactones. As an
extension of the intramolecular NCAL process, pyrrolidine and piperidine fused blactones
were synthesized. Simple g-lactam fused b-lactones were synthesized as a
model study for omuralide, salinosporamide A, and derivative synthesis. Synthesis of asubstituted
aldehyde acids was extensively studied but steric effects from both acid and
amine moieties led to great difficulties in this approach.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/3961 |
| Date | 16 August 2006 |
| Creators | Oh, Seongho |
| Contributors | Romo, Daniel |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 22634315 bytes, electronic, application/pdf, born digital |
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