Publication Date
2010
Document Type
Thesis
Committee Members
Willian Feld (Advisor), Eric Fossum (Committee Chair), Kenneth Turnbull (Committee Member)
Degree Name
Master of Science (MS)
Abstract
Haplomyrtin, a 1-aryl-2,3-naphthalide lignan obtained from Turkish Haplophyllum myrtifolium and Haplophyllum telephioides offers a number of synthetic challenges with the incorporation of two aromatic hydroxyl groups at positions C4 and C7 on the naphthalene ring system and regiospecific condensation of the γ-lactone ring. Improvements towards the total synthesis of haplomyrtin were pursued with commercially available vanillin and piperonal in a total of 8 separate steps. All steps have excellent reproducibility. This strategy includes bromination of protected vanillin to yield 2-(4-(4-methoxybenzyloxy)-2-bromo-5-methoxyphenyl)-1,3-dioxolane and 2-(4-(benzyloxy)-2-bromo-5-methoxyphenyl)-1, 3-dioxolane in 48% and 88% yield respectively, and incorporation of the fully functionalized pendant aryl ring through a lithium-halogen exchange followed by coupling with piperonal. The C4 hydroxyl group is placed by the in-situ formation of an isobenzofuran and subsequent Diels-Alder reaction with DMAD to yield the diester precursor to haplomyrtin, Dimethyl 1-(benzo[d][1,3]dioxol-5-yl)-7-(benzyloxy)-4-hydroxy-6-methoxynaphthalene-2,3-dicarboxylate, in 52% yield.
Page Count
71
Department or Program
Department of Chemistry
Year Degree Awarded
2010
Copyright
Copyright 2010, all rights reserved. This open access ETD is published by Wright State University and OhioLINK.
