N,O-HETEROCYCLICS-14 CONVERSION OF ISOXAZOLIDINES INTO α,β-ENONES

Article abstract of DOI:10.1016/S0040-4020(01)91147-0

Substituted isoxazolidines formed by 1,3-dipolar cycloaddition of nitrones to alkenes undergo ring-opening elimination to α,β-enones when treated with trimethyl phosphate.The reaction involves initial alkylation giving the isoxazolidinium intermediate which collapses to the α,β-enone by a Hofmann-like elimination having an orientation controlled by electronic factors, the first step being rate-determining.