The work described in this thesis is devoted to three separate synthetic methods studies, which represent some past and current interests in our laboratory.
In the first study, a preparation of 2-alkyl- and 2-alkenyl-1,3-cyclohexanediones (2) from 1,5-dimethoxy-1,4-cyclohexadiene (14) is described. Metalation of the diene (14) with tert-butyllithium in tetrahydrofuran solution at low temperature (-78°C) followed by addition of an alkyl or alkenyl halide, in the presence of hexamethylphosphoramide, resulted in a completely regioselective alkylation reaction affording the corresponding
6-alkyl- or 6-alkenyl-1,5-dimethoxy-1,4-cyclohexadiene (16). The latter substances were isolated in good to excellent yields. Simple aqueous hydrolysis of these materials in the absence of air afforded the desired 2-alkyl- and 2-alkenyl-1,3-cyclohexanediones (2) in good yields.
In the second study, an investigation into the regioselective formation
of β-iodo α,β-unsaturated ketones (e.g., (64) and (65)) from unsym-metrical 1,3-cyclohexanediones (63) employing triphenylphosphine diiodide-triethylamine in acetonitrile is described. It has been found that when one of the carbonyl functionalities of the substrate is quite steric-ally hindered the reaction is nearly completely regioselective.
In the third study, the thermal (Cope) rearrangement of the bicyclic dienes (136a), (136b-E), and (136b-2) and the tricyclic dienes (137a-d) is described. In each case, thermolysis of the substrate at 240°C followed by hydrolysis of the intermediate product thus obtained afforded a bicyclo-[3.2.2]non-6-en-3-one, ketones (148), (149), (150) and (151a-d), respectively,
in fair to good overall yield (49-81%). / Science, Faculty of / Chemistry, Department of / Graduate
Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/24295 |
Date | January 1983 |
Creators | Grierson, John Rodney |
Publisher | University of British Columbia |
Source Sets | University of British Columbia |
Language | English |
Detected Language | English |
Type | Text, Thesis/Dissertation |
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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