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SYNTHESIS OF ALL-CARBON SPIROCYCLES BY INTRAMOLECULAR IRON-MEDIATED DIENE/OLEFIN CYCLOCOUPLING

Deslandes, Maria

Abstract Details

2013, Doctor of Philosophy, Case Western Reserve University, Chemistry.
Previous work done in the Pearson laboratory led to the success of an intramolecular double cyclization reaction using cyclohexadiene-Fe(CO)3 with pendant conjugated dienes that are attached via an amide group. Then a novel method was found for the construction of an angular triquinane skeleton by a combination of an iron-promoted tandem double ene-type cyclization followed by a ring contraction. The next logical step is to focus on using this methodology on all-carbon systems which will hopefully produce fused five-membered carbocyclic structures. Efforts were made to streamline the ene cyclization process by investigating direct reactions of alkenyl-substituted cyclohexadienes with iron pentacarbonyl, in an attempt to effect complexation and ene-coupling in one step. There were a variety of steps from the base compound that compromised the diene and its stability making it very difficult to reach the final in situ cyclization reaction. Many different routes were investigated in an effort to overcome this problem, but without success. In view of the complications encountered while attempting to synthesize a simple all-carbon spirocycle by in situ formation of the Fe-complex in the final step, efforts were directed to a model study using a different approach to construct a 4-pentenyl-substituted 2-methylcyclohexadiene-iron complex as a spirocyclization precursor. Cyclization of this material afforded a 2:1 ratio of regioisomers. Two related complexes, in which the pentenyl side chain is replaced by a butenal or hexenoic ester, respectively, were prepared via the reaction of tricarbonyl(2-methylcyclohexadienyl)iron hexafluorophosphate with the alkylzinc-copper reagent derived from methyl 4-iodobutanoate, followed by further manipulation of the ester. Unfortunately, attempted ene-cyclizations of the derived aldehyde and unsaturated ester were uniformly unsuccessful.
Anthony Pearson (Advisor)
John Protasiewicz (Committee Member)
Gregory Tochtrop (Committee Member)
Chung-Chiun Liu (Committee Member)
115 p.

Recommended Citations

Citations

  • Deslandes, M. (2013). SYNTHESIS OF ALL-CARBON SPIROCYCLES BY INTRAMOLECULAR IRON-MEDIATED DIENE/OLEFIN CYCLOCOUPLING [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1354141980

    APA Style (7th edition)

  • Deslandes, Maria. SYNTHESIS OF ALL-CARBON SPIROCYCLES BY INTRAMOLECULAR IRON-MEDIATED DIENE/OLEFIN CYCLOCOUPLING. 2013. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1354141980.

    MLA Style (8th edition)

  • Deslandes, Maria. "SYNTHESIS OF ALL-CARBON SPIROCYCLES BY INTRAMOLECULAR IRON-MEDIATED DIENE/OLEFIN CYCLOCOUPLING." Doctoral dissertation, Case Western Reserve University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1354141980

    Chicago Manual of Style (17th edition)