Trimethylsilyl trifluoromethanesulfonate-promoted cycloaddition of nitrones with silyl enol ethers: synthesis and reactivity of 5-siloxyisoxazohdines

Abstract

In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf), the reaction of nitrones with silyl enol ethers affords 5-siloxyisoxazolidines under mild conditions, in good to excellent yields. 5-Siloxyisoxazolidines can undergo chemoselective reductions to Manoich bases or N-hydroxy-1,3-amino alcohols, and, in the presence of TMSOTf, react with silylated carbon nucleophiles at the acetalic C-5 carbon to give, for example, 5-allyl- and 5-cyano-isoxazolidines.