The usual route for the synthesis of nitrile oxides, viz. chlorination of the oximes (1) to afford the hydroxamyl chlorides f S ) , followed by dehydrohalogenation of (8) with base, was found totally unsuitable for the preparation of ( 2 0 ) -(2d), since chlorine always substituted simultaneously in the group R. However, the alkali salts of the oximes (fc/)-(/d) were readily dehydrogenated with alkyli hypobromite at 0-10 O C to afford the nitrile oxides (2a)-(2c/) in excellent yields. The melting points and yields of compounds (2) and ( 5 ) -(8) are given in Table 1.
M . p . [ " C ]( 2 )Yield 1x1
M . p . [ T I (6)
M . P . I T ](71 Table I Edit. 3, 315 (1964).