Spangler, Charles W.
M.S. (Master of Science)
Department of Chemistry
Organonitrogen compounds; Diels-Alder reaction; Halogenation
3-Acetoxy-l,3,5-hexatriene and 3-ethoxy-l,3,5-hexatriene were prepared by the elimination of HBr from an appropriately substituted dienyl bromide using DBU as the dehydrohalogenating reagent. 3-Ethoxy- 1.3.5- hexatriene was also prepared by the pyrolytic elimination of HOAc from the appropriately substituted dienol. 1-Trimethylsiloxy- 1.3.5- hexatriene was prepared by the addition of chlorotrimethylsilane to 2,4-hexadienal catalyzed by triethylamine and zinc chloride. The route used to prepare 3-acetoxy- and 3-ethoxy-l,3,5-hexatriene involved the synthesis of 3-acetoxy-l,5-hexadien-4-ol and 3-ethoxy- 1.5- hexadien-4-ol. These alcohols were converted to the corresponding allylic bromides and treated with l,8-diazabicyclo[5.4.0]undec-7-ene to effect dehydrohalogenation. 3-Ethoxy-l,5-hexadien-4-ol was also converted to the corresponding acetate, which was then thermolyzed to yield impure 3-ethoxy-1,3,5-hexatriene. The heteroatom substituted-l,3,5-hexatrienes were reacted with acrolein, methacrolein, and methyl vinyl ketone to determine their usefulness as Diels Alder reagents. NMR analysis of the products resulting from the reaction of 3-acetoxy-l,3,5-hexatriene with the dienophiles was accomplished. The Diels Alder products from 3-ethoxy- 1.3.5- hexatriene and 1-trimethylsiloxy-l,3,5-hexatriene were not isolated due to the sensitivity of the ethoxy and trimethylsiloxy functions to preparative glpc. For these adducts the unreacted dienophiles were removed by high vacuum evaporation and the presence of Diels Alder products were confirmed by the nmr signals of the dienophile substituents.
Zentner, Brian A., "Synthesis of 3-acetoxy and 3-ethoxy-1,3,5-hexatrienes and a preliminary evaluation of their effectivness as Diels-Alder reagents" (1981). Graduate Research Theses & Dissertations. 5186.
vi, 62 pages
Northern Illinois University
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