351902-09-5Relevant academic research and scientific papers
Enantiopure and racemic chiral nitronyl nitroxide free radicals: Synthesis and characterization
Hirel, Catherine,Pecaut, Jacques,Choua, Sylvie,Turek, Philippe,Amabilino, David B.,Veciana, Jaume,Rey, Paul
, p. 348 - 359 (2007/10/03)
A synthetic route to a series of homochiral (and achiral) nitronyl nitroxides derived from rac-(and meso)-3,4-dimethyl-3,4-dinitrohexane is described. The two forms of this precursor, meso and rac, were identified unambiguously and reduced to the correspo
Nitronyl and imino nitroxides: Improvement of Ullman's procedure and report on a new efficient synthetic route
Hirel, Catherine,Vostrikova, Kira E.,Pecaut, Jacques,Ovcharenko, Victor I.,Rey, Paul
, p. 2007 - 2014 (2007/10/03)
The synthesis of nitronyl and imino nitroxides has been reexamined with the aim of both increasing yields and of offering opportunities for new structures. The conditions for the formation of 2,3-bis(hydroxyamino)-2,3-dimethylbutane, the key intermediate of Ullman's route, have been carefully studied, and a new procedure is proposed, which affords the free base in a very pure form and up to 60% yield. Full characterization of this intermediate including an X-ray crystal structure is presented. An alternative synthetic route through 2,3-diamino-2,3-dimethylbutane and the corresponding imidazolidines which bypasses the delicate synthesis of the bis(hydroxyamino) compound is described. It is shown that 3-chloroperbenzoic acid is an effective oxidant for the transformation of adequately substituted imidazolidines into nitronyl nitroxides, which are obtained in high yield. An illustration of the potentialities of this new route, a new nitronyl nitroxide with two ethyl substituents in positions 4 and 5 of the imidazoline ring, is reported. The scope and limitations of the two routes are discussed.
Total Synthesis and Determination of the Absolute Configuration of Frondosin B
Masayuki, Inoue,Carson, Mattew W.,Frontier, Alison J.,Danishefsky, Samuel J.
, p. 1878 - 1889 (2007/10/03)
Two concise syntheses of (+/-)-frondosin B (1), an interleukin-8 receptor antagonist, have been achieved from commercially available 5-methoxysalicylaldehyde. The seven-membered ring in ketone 33, the common intermediate for both syntheses, was built by a
