3-FERROCENYL-3-(1-NAPHTHYL)CYCLOPROPENE - SYNTHESIS, STRUCTURE, AND CHEMICAL-TRANSFORMATIONS

Crystalline 3-ferrocenyl-3-(l-naphthyl)cyclopropene was prepared by de hydrobromination of Z- and -2-bromo-1-ferrocenyl-1-(1-naphthyl)-cyclop ropanes by (BuOK)-O-t in DMSO. The resulting compound and the starting Z-monobromocyclopropane were characterized by X-ray diffraction analy sis. The obtained cyclopropene reacts with 1,3-diphenylisobenzofuran t o give a [4+2]-cycloadduct. The small ring opens upon treatment with H BF4 etherate to afford isomeric Z- and E-prop-1-enes and 1-ferrocenyl- 3H-benzo[e]indene. Thermolysis of this cyclopropene results in the for mation of 1-ferrocenyl-9bH-benzo[e]indene. In all cases, opening of th e small ring is accompanied by exclusive alkylation of the naphthalene moiety.