Studies on chrysanthemic acid—III

Chrysanthemyl isocyanate (4, cis: trans = 5 5 ) was prepared from chrysanthemic acid (1, cis: trans = 4 6 ) via the corresponding acid chloride (2) and acid aride (3). In these successive reactions, any appreciable change of the isomer ratio was not observed, indicating that the Curtius rearrangement proceeds through a concerted process. Chrysanthernoyl-isocyanate (6) and -isothiocyanate (7) were prepared from 2 and some reactions of these isocyanates, (4, 6, and 7) were carried out to obtain chrysanthemyl and chrysanthemoyl urea and urethane derivatives (8a-j, 9a, b, and 10a, b), imidazotrione derivatives (11a, b) and a thiadiazole derivative (12). The reaction of chrysanthemamide (5a, b) with oxalyl chloride to give a spiro oxazolidine-4,5-dione (17a, b) was investigated and its mechanism proposed.