|Title:||Synthetic Routes to Lignans|
|Other Titles:||Isolation and Structure Elucidation of Constituents of Elaegia Utilis|
|???metadata.dc.contributor.*???:||Prof. Robert Stevenson |
|Publisher:||Addis Ababa University|
|Abstract:||Synthetic Routes to Lignans 2,3-Diaroylbutanes were selectively converted with high stereospecificity to 2,5~diaryl“3,4-dimethylfurans or 2,3- diarylbutanes. The racemic forms of the dibenzylbutane lignans, dihydroguaiaretic acid dimethyl ether 26a, austrobilignan- 5 26b and austrobilignan-6 26 e * and the diaryltetrahydrofuran lignans, veraguensin 27a and its piperonyl analogue 27 b have been readily synthesized. The synthesis of the dissimilar substituted 2^"diaryltetrahydrofuran austrobilignan -7 27er was limited by isomer formation and separation difficulty. A short convenient synthesis of the aryltetralin lignan, galbulin 37a and the all-trans tetrahydrofuran lignan,galbelgiri 31a are also reported. 1,4-Diarylbutanes undergo intramolecular oxidation with vanadium oxytrifluoroide to yield dibenzo [a,c] cyclooctenes. Short synthetic routes to the lignan , (+ ) -deoxyschizandrin 43d have been developed from 3,4, 5-trimethoxypropiophenone. Isolation and Structure Elucidation of Constituents of Elaegia Utilis By neutral solvent extraction of Elaegia utilis resin, there have been isolated the flavone apigenin 12 and the tetracyclic triterpenoid , isofouquierol 10 whose structure has been confirmed. By saponification of the insoluble residue, dammarenediol-II 1 ( in dimorphic form ) and a new triterpenoid , 30 » 20S , 26-trihydroxydammar~24-ene 6 were obtained from the neutral fraction|
|Description:||A Dissertation Presented to the Faculty of the Graduate School of Arts and Sciences Brandeis University Department of Chemistry|
|Appears in Collections:||Thesis - Chemistry|
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