Wan, Shuangyi
(2009)
Studies on the Structure/Reactivity Relationships of Bicyclic Epoxonium Ions and Tethered Nucleophiles. Efforts towards the Total Synthesis of (+)-Lactodehydrothyrsiferol and its Analogs. Multicomponent Approach to the Synthesis of Oxidized Amides through Nitrile Hydrozirconation.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
A systematic study on the structure/reactivity relationships of bicyclic epoxonium ions towards tethered nucleophiles has been conducted. The cyclization results show that bicyclo[3.1.0] epoxonium ions have a significant to exclusive preference for exo-cyclizations while bicyclo[4.1.0] epoxonium ions have a strong preference for endo-cyclizations.A convergent approach towards the total synthesis of polycyclic ether natural product (+)-lactodehydrothyrsiferol and its analogs is currently being pursued. This route includes the stereoselective reduction of the bicyclo[3.2.1] ketal which could be prepared from coupling of the functionalized aldehyde and vinyl iodide. Both enantiopure fragments can be obtained from cyclizations of the diepoxide and the monoepoxide, respectively. Key transformations involve two asymmetric epoxidations, a cascade cyclization of diepoxide, a Cr/Ni-mediated coupling reaction and a stereoselective reduction of bicyclo[3.2.1] ketal.An efficient one-pot synthesis of oxidized amides from nitrile hydrozirconation has been developed. From the common acylimine intermediates, acyl aminals can be accessed through alcohol addition, acyl hemiaminals can be accessed through water addition and enamides can be accessed through tautomerization.
Share
| Citation/Export: |
|
| Social Networking: |
|
Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
|
| Date: |
29 January 2009 |
| Date Type: |
Completion |
| Defense Date: |
23 June 2008 |
| Approval Date: |
29 January 2009 |
| Submission Date: |
1 July 2008 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Chemistry |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
cyclization; epoxide; hydrozirconation; lactodehydrothyrsiferol; oxidized amide |
| Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-07012008-135252/, etd-07012008-135252 |
| Date Deposited: |
10 Nov 2011 19:49 |
| Last Modified: |
15 Nov 2016 13:45 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/8248 |
Metrics
Monthly Views for the past 3 years
Plum Analytics
Actions (login required)
 |
View Item |
![[feed]](/images/feed-icon-32x32.png){kind=icon}