Browsing by Author "Biftu, Tesfaye"

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    A Dissertation Presented to the Faculty of the Graduate School of Arts and Sciences of Braitdeis University, Waltham , Massachusetts
    (Addis Ababa Universty, 1978-08) Biftu, Tesfaye; Stevenson, Robert (Professor)
    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 yield dibenzo [a,c] cyclooctenes. Short synthetic routes to the lignan , (+ )-deoxyschizandrin 43d have been developed from 3,4, 5-trimethoxypropiophenone.