Reactions of 3,3-dialkyl-2,3-dihydro-6-trifluoromethyl-4-pyrones with hydroxylamine. Synthesis and structures of 5-(1,1-dialkyl-2-hydroxyethyl)-5-hydroxy-3-trifluoromethyl-Delta(2)-isoxazolines

The reactions of 3,3-dialkyl-2,3-dihydro-6-trifluoromethyl-4-pyrones with h ydroxylamine hydrochloride afforded regioisomeric 3(5)-(1,1-dialkyl-2-hydro xyethyl)-5-hydroxy-5(3)-trifluoromethyl-Delta(2)-isoxazolines depending on the reaction conditions. The title compounds were also prepared from 2,2-di alkyl-5-amino-1-hydroxy-6,6,6-trifluorohex-4-en-3-ones. The above dihydropy rones reacted with hydroxylamine (base) to yield 3-(1,1-dialkyl-2-hydroxyet hyl)-5-hydroxyamino-5-trifluoromethyl-Delta(2)-isoxazolines.