eprintid: 9310 rev_number: 4 userid: 6 dir: disk0/00/00/93/10 datestamp: 2011-11-10 20:01:41 lastmod: 2016-11-15 13:50:01 status_changed: 2011-11-10 20:01:41 type: thesis_degree metadata_visibility: show contact_email: liy3@pitt.edu item_issues_count: 0 eprint_status: archive creators_name: You, Lingfeng creators_email: liy3@pitt.edu creators_id: LIY3 title: SYNTHETIC EFFORTS TOWARDS INGENOL CROSS-CONJUGATED TRIENES AND THEIR APPLICATION TO RAPID INCREASES IN MOLECULAR COMPLEXITY ispublished: unpub divisions: sch_as_chemistry full_text_status: public keywords: Alder-ene; cross-conjugated triene; ingenol; rhodium abstract: Synthesis of the ingenol skeleton using a Pauson-Khand reaction as the key step was investigated. Although the Pauson-Khand reaction failed to provide the highly strained ingenol skeleton, several relatively complex Pauson-Khand precursors were prepared in about ten steps. The scope and limitation of the Pauson-Khand reaction in accessing highly strained molecules were studied. A rhodium(I)-catalyzed allenic Alder-ene reaction was developed that provides cross-conjugated trienes in good yields. This method shows enticing functional group compatibility, and progress has been made to increase the stereoselectivity of the olefinic side chain via iridium(I) catalysis. A consecutive one-pot Alder-ene/[4+2]/[4+2] reaction has been developed to demonstrate the potential of the cross-conjugated triene for accessing polycyclic compounds. The reaction sequence is highly selective with the Alder-ene and the first Diels-Alder reaction only providing a single isomer and the intermolecular [4+2] cycloaddition giving two endo addition products resulting from addition of the dienophile to either face of the diene. The transformation is highly atom-efficient with all the atoms of the starting dialkynyl allenes and the dienophiles appearing in the products. date: 2006-03-30 date_type: completed institution: University of Pittsburgh refereed: TRUE etdcommittee_type: committee_chair etdcommittee_type: committee_member etdcommittee_type: committee_member etdcommittee_type: committee_member etdcommittee_name: Brummond, Kay M etdcommittee_name: Floreancig, Paul etdcommittee_name: Day, Billy etdcommittee_name: Wipf, Peter etdcommittee_email: kbrummon@pitt.edu etdcommittee_email: florean@pitt.edu etdcommittee_email: bday@pitt.edu etdcommittee_email: pwipf@pitt.edu etdcommittee_id: KBRUMMON etdcommittee_id: FLOREAN etdcommittee_id: BDAY etdcommittee_id: PWIPF etd_defense_date: 2005-08-02 etd_approval_date: 2006-03-30 etd_submission_date: 2005-09-01 etd_access_restriction: immediate etd_patent_pending: FALSE assigned_doi: doi:10.5195/pitt.etd.2011.9310 thesis_type: dissertation degree: PhD committee: Kay M. Brummond (kbrummon@pitt.edu) - Committee Chair committee: Paul Floreancig (florean@pitt.edu) - Committee Member committee: Billy Day (bday@pitt.edu) - Committee Member committee: Peter Wipf (pwipf@pitt.edu) - Committee Member etdurn: etd-09012005-105944 other_id: http://etd.library.pitt.edu/ETD/available/etd-09012005-105944/ other_id: etd-09012005-105944 citation: You, Lingfeng (2006) SYNTHETIC EFFORTS TOWARDS INGENOL CROSS-CONJUGATED TRIENES AND THEIR APPLICATION TO RAPID INCREASES IN MOLECULAR COMPLEXITY. Doctoral Dissertation, University of Pittsburgh. (Unpublished) document_url: http://d-scholarship-dev.library.pitt.edu/9310/1/LingfengYou.pdf