The title compound (4) has been prepared by treatment of diketene with N, O-bis (trimethylsily1) hydroxylamine (2) to give N-(trimethylsiloxy)-N-(trimethylsilyl) acetoacetamide (3) as a stable liquid. Treatment of 3 with methanolic HCl removed the Me3Si protective groups and cyclized the resulting hydroxamic acid to isoxazole 4 in good yield. The dianion of 4 was generated with lithium diisopropylamide and was found to ...
