This thesis describes work leading to the completion of a total synthesis of the sesquiterpenoids (±)-prezizanol (188) and (±)-prezizaene (6).
The known alcohol 128 was transformed, in three steps, into the endo-monochloride 156. The commercially available alcohol 129 was converted, in a two step sequence, into the vinyl iodide 127. Palladium catalyzed coupling of the vinyl iodide 127 with an organozinc compound derived from the chloride 156 provided the bicyclo[3.1.0]hexane 165.
The bicyclo[3.1.0]hexane 165 was elaborated, in three steps, into the ester 172. Treatment of this ester with lithium diisopropylamide, followed by kinetic protonation of the resultant enolate anion, provided the endo-(1-alkenyl)-bicyclo[3.1.0]hex-2-ene 123, which cleanly underwent a Cope rearrangement to provide the bicyclo[3.2.1]octadiene 121. An attempt to cleanly synthesize 121 via the Cope rearrangement of the exo-(1-alkenyl)bicyclo-[3.1.0]hex-2-ene 122 was unsuccessful.
A six step sequence was used to synthesize the mixture of silyl ethers 186 and 187 (88:12, respectively) from the bicyclo[3.2.1]octadiene 121. (±)-Prezizanol (188) was prepared, in a series of seven steps, from the silyl ether 186. Dehydration of (±)-prezizanol (188) provided (±)-prezizaene (6) in 2.2% overall yield from the alcohol 128. [Formula Omitted] / Science, Faculty of / Chemistry, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/27441 |
| Date | January 1987 |
| Creators | Marrs, Peter Scot |
| 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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