New base induced rearrangements of 4-acylisoxazolidines. Anionic reactional cascades from five membered rings to either four membered rings or open chain compounds

Treatment of 2,3,3-triphenyl-4-formylisoxazolidines with bases triggers an unprecedented anionic reactional cascade which terminates with a 2-iminooxetane derivative. In the case of 2,3,3-triphenyl-4-methoxycarbonyl isoxazolidine the multistep rearrangement gives rise to a derivative of malonic acid.