The synthesis and chemical reactivity in Diels-Alder reactions of the
title compound 6 is described. When 6 was reacted with N-phenylmaleimi
de, a 3.1 mixture of isomers exo 14a and endo 14b was found, while wit
h triazolinedione 13, a novel ferrocenyl heterocycle 15 was formed. Th
e structures for 14b and 15 were confirmed by X-ray diffraction analys
is. (C) 1997 Elsevier Science Ltd.