A Simple Environmentally Friendly Method for the Synthesis of Hydroxyisoxazolidine Derivatives

Abstract

A series of 5-hydroxyisoxazolidines has been successfully synthesized through tris(hydroxymethyl)aminomethane (TRIS) buffered hydroxylamine hydrochloride and α, βunsaturated ketones reaction. This synthetic approach can be considered as environmentally friendly because of the use of non-toxic and non-hazardous reagents at room temperature. The reaction is also metal-free and generates minimum non-toxic waste. The structure of 5-hydroxyisoxazolidines was confirmed not only by extended NMR analysis but by a series of elimination and acetylation reactions. Hydroisoxazolidines are obtained as a mixture of diastereomers (cis-, trans-and N-invertomers). Usually, three sets of 1 HNMR signals are observed for that class of compound (especially for protons H3 and both H4). The analysis of cis-and trans-isomerization of the product 2 b has been conducted.

Facile synthesis of (polyfluoro)alkanesulfinyl 4-isoxazolines: a stepwise solvent- and catalyst-free approach or a one-pot process in water

“…[3][4][5][6][7] 1,3-Dipolar cycloadditions between nitrones and alkynes or allenes are the most common strategy to synthesize 4-isoxazolines. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] Regioisomers are often obtained in cycloaddition reactions between nitrones and asymmetrically substituted alkynes or allenes. 8,9 However, with some monosubstituted or electrondeficient alkynes, 4-isoxazolines can be achieved with good regioselectivity, which has been explained by FMO analysis.…”