Chemoselective isomerization of amide-substituted oxetanes with Lewis acid to give oxazine derivatives or bicyclic amide acetals

The Lewis-acid catalyzed isomerization of secondary and tertiary amide-substituted oxetanes takes place chemoselectively, giving 5-hydroxymethyl-5,6-dihydro-4H-1,3-oxazines and reactive amide acetals consisting of a bicyclo[2.2.2]octane skeleton, respectively.