dc.contributor.advisor | Minter, David E. | |
dc.contributor.author | Zhang, Yi | en_US |
dc.date.accessioned | 2019-10-11T15:10:04Z | |
dc.date.available | 2019-10-11T15:10:04Z | |
dc.date.created | 2004 | en_US |
dc.date.issued | 2004 | en_US |
dc.identifier | aleph-1039954 | en_US |
dc.identifier.uri | https://repository.tcu.edu/handle/116099117/31843 | |
dc.description.abstract | The crinine-type alkaloids are characterized by the presence of the 5,10b-ethano-phenanthridine skeleton and represent an important subgroup within the large family of amaryllidaceae alkaloids. Based on the obvious structural relationship between crinine alkaloids and isoquinoline, a novel and concise synthetic approach towards these alkaloids from isoquinoline has been established. The viability of using a ring closure metathesis (RCM) reaction to create the C ring was investigated with a model system synthesized from 4-allylisoquinoline. A reductive alkylation sequence followed by the addition of allylmagnesium bromide to the resulting imine created a trans -3,4-diallyltetrahydroisoquinoline precursor to the crinane skeleton. RCM produced the desired phenanthridine derivative containing a two-carbon substituent for elaboration to the ethano bridge. Since the Grignard addition to the imine in the model study was not stereoselective, an alternate route was designed to close the D ring first. A Mitsunobu reaction on the 3-allyl-4,4-bis(2-hydroxyethyl)tetrahydroisoquinoline established the ethano bridge with complete control of the stereochemistry such that the remaining allyl and hydroxyethyl groups were trans . Subsequent conversion of the hydroxyethyl group to allyl followed by RCM gave the crinane skeleton with the required trans -fused C ring. This methodology has been extended to the total synthesis of the (¿)-crinane degradation product (¿)-?-2(3)-crinane and (¿)-elwesine. | |
dc.format.extent | ix, 123 leaves : illustrations | en_US |
dc.format.medium | Format: Print | en_US |
dc.language.iso | eng | en_US |
dc.relation.ispartof | Texas Christian University dissertation | en_US |
dc.relation.ispartof | AS38.Z382 | en_US |
dc.subject.lcsh | Alkaloids | en_US |
dc.subject.lcsh | Isoquinoline | en_US |
dc.title | Synthetic approaches towards the skeleton of the crinine-type amaryllidaceae alkaloids from isoquinoline and total synthesis of (±)-elwesine | en_US |
dc.type | Text | en_US |
etd.degree.department | Department of Chemistry | |
etd.degree.level | Doctoral | |
local.college | College of Science and Engineering | |
local.department | Chemistry and Biochemistry | |
local.academicunit | Department of Chemistry | |
dc.type.genre | Dissertation | |
local.subjectarea | Chemistry and Biochemistry | |
dc.identifier.callnumber | Special Collections: AS38 .Z382 (Non-Circulating) | |
etd.degree.name | Doctor of Philosophy | |
etd.degree.grantor | Texas Christian University | |