CYCLOADDITION OF NITRONES TO 1,3-DIARYLPROPENONES AND SUBSEQUENT TRANSFORMATIONS OF THE RESULTING ISOXAZOLIDINES
DOI:
https://doi.org/10.1007/5707Keywords:
chalcones, isoxazolidines, nitrones, 1, 3-dipolar cycloaddition, reductionAbstract
Ketonitrones containing two ester groups react regio- and stereoselectively with 1,3-diarylpropenones to form isoxazolidines with ester groups at position 3 of the ring. The action of zinc in acetic acid on these isoxazolidines causes opening of the ring with the formation of 3-amino alcohols, the subsequent cyclization of which leads to polysubstituted lactones. Reduction of the benzoyl group of isoxazolidine with sodium borohydride leads, as a result of subsequent transformations, to the formation of substituted 1,3,4-triaryl-6-oxodihydro-1H,3H-furo[3,4-c]isoxazole-6a(6H)-carboxylates as single diastereomers.
Authors: Ekaterina V. Sirotkina, Mariia M. Efremova, Galina L. Starova, Mikhail A. Kuznetsov, Alexander P. Molchanov*