Isolated from Spongosorites sp., Dragmacidin E is of synthetic interest due to its biological properties and novel molecular structure. A promising therapeutic target, its synthetic challenge is attributed to its heptacyclic core. In this study, we propose the synthesis of a Dragmacidin E heptacyclic core precursor, mediated through a Lewis acid (LA) mediated cyclization of an acceptoreptor-donor (AAD) cyclopropane. Utilizing a model study, alkoxy AAD cyclopropanes were investigated to develop a protocol for precursor synthesis. After generating various ethyl-α-diazobenzoyl acetate derivatives, the metal catalyzed cyclopropanation reaction of these compounds was studied. With vinyl acetate and Rh2esp2, acetoxy AAD cyclopropanes were synthesized in yields ranging from 12 % - 53 %. These cyclopropanes were successfully generated and rearrangement into dihydrofuran products was avoided. To complete our model study, LA cyclization of acetoxy AAD cyclopropanes was studied. Using stoichiometric quantities of TiCl4<.sub>, naphthol derivatives were synthesized in one step.
| Identifer | oai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-5116 |
| Date | 13 December 2014 |
| Creators | Reyes, Yahaira De Bary |
| Publisher | Scholars Junction |
| Source Sets | Mississippi State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
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