3-allryl-2, 4-pentanedione and diethyl nitrosomalonate (see the Experimental Section). The usual procedure for this la (R= H) 4b (R= CH3) conversion is perchlorination of the 5-methyl group followed by ethanolysis? This method, however, turned out to be unsatisfactory for the preparation of large amounts of the diesters 1 required in the present work. Thus, a different approach to compounds 1 was chosen, consisting
