Friedel-Crafts acetylation of [h5-(ferrocenylmethyl)cyclopentadienyl]dicarbonyl-nitrosylchromium (hereafter called cynichrodenylferrocenylmethane) (3) has afforded (1′-acetylferrocenyl)cynichrodenylmethane (5), (3-acetylferrocenyl)cynichrodenylmethane (6) and (2-acetylferrocenyl)cynichrodenylmethane (7) in 87% total yield. The relative reactivity and orientation of the three Cp rings on 3 toward the Friedel-Crafts reaction are discussed. The structure of 6 has been solved by an X-ray diffraction study: space group P21/c, a 22.445(4), b 7.129(2), c 11.467(4) ?, β 93.06(2)°, and Z = 4. The nitrosyl group is located at the site toward the exocyclic methylene carbon with a twist angle of 1.8°, and the two cyclopentadienyl rings of ferrocenyl moiety exhibit an average twist angle of 17°. ? 1990.
