Several t-butoxycarbonyl derivatives of oximes were prepared through the corresponding oxime chloroformates. Of these, diethyl (t-butoxycarbonyloxyimino) malonate and 2-(t- butoxycarbonyloxyimino)-2-phenylacetonitrile were utilized for the preparation of t- butoxycarbonylamino acids under various conditions. The results are summarized in a table.