Regiodivergence in the Cycloadditions between a Cyclic Nitrone and Carbonyl-Type Dipolarophiles
Alberto Esteban1, Carlos T Nieto1, Narciso M Garrido1
1Organic Chemistry Department, Chemical Sciences Faculty, University of Salamanca, Plaza de los Caídos 1-5, 37008 Salamanca, Spain.
None:
The present report details the 1,3-dipolar cycloaddition between a chiral cyclic nitrone (1) and different carbonyl-type dipolarophiles, thus confirming the regiodivergence observed due to the cyclic nature of the dipolarophile source. An ortho regioselectivity is observed in the resulting isoxazolidines when the dipolarophile is acyclic, whereas the meta adducts are obtained from the cyclic dipolarophiles. This evidence is supported by both electronic calculations and X-ray diffraction.
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