Ros Lao, AbelÁlvarez González, EleuterioDietrich, HansjörgBatarda Fernandes, RosarioLassaletta Simón, José María2018-02-192018-02-192005Ros Lao, A., Álvarez González, E., Dietrich, H., Batarda Fernandes, R. y Lassaletta Simón, J.M. (2005). A Practical Synthesis of Enantiopure 4,5-Dihydroisoxazole-5-carboxylic Acids. Synlett, 19, 2899-2904.0936-5214https://hdl.handle.net/11441/70420The 1,3-dipolar cycloaddition of a variety of aromatic and aliphatic nitrile oxides to 2,5-trans-2,5-diphenylpyrrolidine derived acrylamide and cinnamamide efficiently affords the corresponding 4,5-dihydroisoxazole-5- carboxamides in a highly regio- and stereoselective manner. The cycloaddition of aliphatic nitrile oxides to the analogue methacrylamide proceeds also smoothly to afford the expected cycloadducts in moderate yields and very high regio- and stereoselectivity. In sharp contrast, aromatic nitrile oxides react with the same amide to afford 5-methyl-4,5-dihydroisoxazole-5-carboxamides in higher yields but as near 1:1 mixtures of diastereoisomers. Acid hydrolysis of these products afforded enantiopure 4,5-dihydroisoxazole-5-carboxylic acids. © Georg Thieme Verlag Stuttgart.application/pdfengAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Asymmetric synthesisCycloadditionsHeterocyclesIsoxazolinesNitrile oxidesinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccesshttps://doi.org/10.1055/s-2005-921894