The reaction of alpha-bromoketone oximes with isocyanides and sodium c
arbonate leads to a new formation of 5-aminoisoxazole derivatives. The
reaction probably involves the intermediacy of a nitrosoalkene genera
ted in situ. Good yields are obtained for electron deficient ketone ox
imes such as ethyl bromopyruvate oxime; the use of a trifluoromethyl s
ubstituted oxime gives a high efficient formation of trifluoromethyl i
soxazoles. (C) 1997 Published by Elsevier Science Ltd.