摘要:
Treatment of 2-bromo aldehydes and ethyl nitroacetate with alumina without solvent, or in solution with a tertiary base, at room temperature gives the diastereoisomeric title compounds in fair yields by a tandem nitroaldol reaction-cyclization sequence opening a new route for the preparation of trans and cis 4-hydroxylated 2-isoxazolines in a predictable way.