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Ashburn, Stephen Patrick 2014-12-15T23:18:24Z 2014-12-15T23:18:24Z 10000-01-01 1985 1985 Oxazoline N-oxides have been prepared in medium to high yields under mild conditions by condensation of 2-(hydroxyamino)-2-methyl-1-propanol with ortho esters or amide acetals. 3 + 2 Cycloaddition reactions of the oxazoline N-oxides and the related pyrroline N-oxides with phenyl isocyanate, dimethyl acetylenedicarboxylate, methyl phenylpropiolate, phenylpropiolonitrile, methyl acrylate, and acrylonitrile were carried out. The reaction of 4,4-dimethyl-2-phenyloxazoline N-oxide with acetylenic dipolarophiles in concentrated solutions of dimethylamine hydrochloride in dichloromethane, however, led to the formation of isoxazoles. Competitive experiments demonstrated that 2,4,4-trimethyloxazoline N-oxide is at least 6,800 times more reactive toward phenyl isocyanate than the analogous 2,5,5-trimethylpyrroline N-oxide, and is 160 times more reactive toward dimethyl acetylenedicarboxylate than the pyrroline N-oxide. Rate constants for the 3 + 2 cycloaddition reactions of 4,4-dimethyl-2-phenyloxazoline N-oxide and 5,5-dimethyl-2-phenylpyrroline N-oxide with phenyl isocyanate and dimethyl acetylenedicarboxylate were measured. These data indicate that the oxazoline N-oxide is approximately 76,000 times more reactive toward phenyl isocyanate than the pyrroline N-oxide, and is 70 times more reactive toward dimethyl acetylenedicarboxylate than the pyrroline N-oxide. An explanation for the enhanced reactivity of oxazoline N-oxides is forwarded on the basis of frontier molecular orbital theory. Made available in DSpace on 2014-12-15T23:18:24Z (GMT). No. of bitstreams: 1 8511575.pdf: 4900656 bytes, checksum: 2d423b33ac957de3114aba159ddf20a1 (MD5) Previous issue date: 1985 Embargo set by: Seth Robbins for item 70454 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 191 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985. http://hdl.handle.net/2142/70288 (UMI)AAI8511575 Chemistry, Organic Preparation and Cycloaddition Reactions of Oxazoline Nitrogen Oxides text Chemistry Chemistry University of Illinois at Urbana-Champaign Dissertation Ph.D.