Fu, Dezhi
(2011)
I. LEWIS BASE-CATALYZED ALDOL REACTION IN THE TOTAL SYNTHESIS OF ERYTHRONOLIDE B; II. EFFORTS TOWARDS THE TOTAL SYNTHESIS OF AMPHIDINOLIDE H.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Lewis base (trimethylsilylquinine and trimethylsilylquinidine) catalyzed acyl halide-aldehyde cyclocondensation (AAC) reactions have been developed to prepare synthetically important bispropionate units previously by the Nelson group. A new Lewis base-catalyzed diastereoselective Mukaiyama aldol reaction has extended this bispropionate unit preparation methodology to all-syn bispropionates which widely occurred in polypropionate natural products. By using phenoxides as Lewis base catalysts, enol silanes were activated and underwent a Felkin attack on an aldehyde through an antiperiplanar transition state to generate all-syn bispropionate product in high yields and excellent diastereoselectivities.All-syn bispropionate prepared from the Lewis base-catalyzed diastereoselective Mukaiyama aldol reaction has been untilized in natural product synthesis of erythronolide B establishing ¡°syn,syn,syn¡± stereochemical relationships from C2-C5.Studies towards the total synthesis of the cytotoxic marine macrolide amphidinolide H have been disclosed. By exploiting AAC methodology, several key stereochemical relationships present in major fragments 198 and 199 were established. A highly enantioselective synthesis of methyl ketone 200 was realized from commercially available (S)-(−)-glycidol. Iodide 198 was coupled with boronic ester 199 via an efficient Suzuki reaction to form a C7-C20 fragment.
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Details
| Item Type: |
University of Pittsburgh ETD
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| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
22 June 2011 |
| Date Type: |
Completion |
| Defense Date: |
8 April 2011 |
| Approval Date: |
22 June 2011 |
| Submission Date: |
15 April 2011 |
| 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: |
AAC; Amphidinolide H; Erythronolide B; Lewis Base; Macrolides; Mukaiyama Aldol; Ployketide |
| Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-04152011-183517/, etd-04152011-183517 |
| Date Deposited: |
10 Nov 2011 19:37 |
| Last Modified: |
15 Nov 2016 13:40 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/7211 |
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