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Synthetic approach to the agelasimines Dotse, Anthony Kwabla
Abstract
Aside from the structural interest and the success achieved in annulation methods as exemplified in schemes 6 and 7 in this laboratory, synthetic work on the agelasimines A and B and their quartenary 9-methyladenine derivative (44) was encouraged by the presence of a variety of biological activities in these natural products. Another aim of this thesis is to confirm the generality of the synthetic method as applied to the total synthesis of ambliol B (48). Copper(I) mediated conjugate addition of allylmagnesium bromide to 3,4-dimethy1-2-cyclohexen-l-one (63), followed by trapping of the enolate generated with trimethylsilyl chloride, produced the silyl enol ether (62), which was converted to the Mannich base (61). Oxidation of this compound with m-CPBA gave an amine-oxide intermediate which eliminated N , N - dimethylhydroxylamine to give the enone (60). Conjugate addition of the novel vinylgermane cuprate (19) to this enone and treatment of resultant ketone (80) with iodine gave the iodide (59). This iodide was employed as the cyclization precursor to the trans-fused substituted bicyclo[4.4.0]decananol (58). Cyclopropanation of the exocyclic double bond in (58) occurred chemoselectively and gave the cyclopropane (67). The remaining double bond was ozonized and the ozonide cleaved to generate an aldehyde which was reduced to the primary alcohol (93). Hydrogenolysis of the cyclopropane ring of this diol provided the diol (55), which is a possible precursor for the synthesis of the agelasimines A (42), B (43) and their quartenary 9-methyladenine derivative (44). (Abstract contains diagrams)
Item Metadata
Title |
Synthetic approach to the agelasimines
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1992
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Description |
Aside from the structural interest and the success achieved in
annulation methods as exemplified in schemes 6 and 7 in this
laboratory, synthetic work on the agelasimines A and B and their
quartenary 9-methyladenine derivative (44) was encouraged by the
presence of a variety of biological activities in these natural products.
Another aim of this thesis is to confirm the generality of the
synthetic method as applied to the total synthesis of ambliol B (48).
Copper(I) mediated conjugate addition of allylmagnesium
bromide to 3,4-dimethy1-2-cyclohexen-l-one (63), followed by
trapping of the enolate generated with trimethylsilyl chloride,
produced the silyl enol ether (62), which was converted to the
Mannich base (61). Oxidation of this compound with m-CPBA gave
an amine-oxide intermediate which eliminated N , N -
dimethylhydroxylamine to give the enone (60). Conjugate addition
of the novel vinylgermane cuprate (19) to this enone and treatment
of resultant ketone (80) with iodine gave the iodide (59). This
iodide was employed as the cyclization precursor to the trans-fused
substituted bicyclo[4.4.0]decananol (58). Cyclopropanation of the
exocyclic double bond in (58) occurred chemoselectively and gave
the cyclopropane (67). The remaining double bond was ozonized
and the ozonide cleaved to generate an aldehyde which was reduced
to the primary alcohol (93). Hydrogenolysis of the cyclopropane
ring of this diol provided the diol (55), which is a possible precursor
for the synthesis of the agelasimines A (42), B (43) and their
quartenary 9-methyladenine derivative (44).
(Abstract contains diagrams)
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Extent |
2280779 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2008-12-15
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0059598
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1992-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.