STUDIES IN THE CYCLOPROPARENE SERIES - HETEROCYCLIC SUBSTITUTED METHYLIDENECYCLOPROPA[B]NAPHTHALENES

1H-Cyclopropa[b]naphthalene 7 is converted into a range of 6 pi 5-atom -substituted methylidene derivatives 12e-j, the pyridyl analogues 12k and l, and the phenylsulfanyl analogue 12m by way of the 1,1-disilyl c ompound 9 and Peterson olefination in improved procedure. The spectros copic properties of the compounds are reported and their behaviour as possible lumophores assessed. Crystal structures of the dimethylaminop henyl 12c,d, and the thienyl 12e derivatives are presented. The perman ent dipole moments of the mono-substituted 12e and k have been measure d as 2.76, and 3.37 D, respectively, and that of the dithenyl 12f as 9 .06 D.