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- Karlsson, Staffan, et al.
(author)
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Organocatalysts Promote Enantioselective 1,3-Dipolar Cycloadditions of Nitrones with 1-Cycloalkene-1-carboxaldehydes
- 2003
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In: European Journal of Organic Chemistry. - : Wiley. - 1434-193X .- 1099-0690. ; 2003:15, s. 2782-2791
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Journal article (peer-reviewed)abstract
- In the presence of enantiopure organocatalysts, 1-cycloalkene-1-carboxaldehydes and various nitrones furnished fused isoxazolidines. Thus, some chiral pyrrolidinium salts catalyzed the formation of such cycloadducts in high diastereo- and enantioselectivity (up to 92% ee). The predominant diastereomer, the exo one, was mostly obtained in excellent diastereoselectivity (> 99:1 dr). Furthermore, after recrystallization of one of the cycloadducts, this was obtained enantiomerically pure (> 99% ee). The absolute configuration of one of the cycloadducts was determined.
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