Abstract The reaction of Me 3 SiX (X= Cl, I, NCS, CN, N 3 NEt 2, SMe, H (in Et 3 SiH), F, OMe, NCO, O 2 CMe) with acetonitrile oxide led to the formation of O- trimethylsilylacetohydroxamoyl adducts for the first seven members of the series. A rationale is given for the observed reactivity.