Solketol crotonates

Chiral crotonates derived from S-citroncllol, l-(—)-menthol, and S-solketol undergo 1,3-dipolar cycloaddition with cyclic and acyclic nitrones.66 Asymmetric 1,3-dipolar cycloaddition of optically active hifluoromethylated a, /l-unsaturated aiyl sulfones (43) with nitrones yield the corresponding isoxazolidmes (44) and (45) with high regio- and... 

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