Studies in the Cycloproparene Series: 1,1-Dichloro-1h-Cyclopropa[l]Phenanthrene

Abstract

Phenanthrenes (5c-e) substituted at the 9-position with sulfur or selenium undergo addition of dichlorocarbene to provide the corresponding 1a-substituted 1a,9b-dihydro-cyclopropa[l]phenanthrenes (6c-e). Oxidation of the phenylselenocyclopropaphenanthrene (6e) followed by selenoxide elimination provides products resulting from cleavage of the three-membered ring. Complementary deuterium labelling studies show that the major pathway for this elimination proceeds via 1,1-dichloro-1H-cyclopropa[l]phenanthrene (4b).