Approaches to 1H-Cyclopropaphenanthrenes. Eliminations with 1a,9b-Dihydro-1H-cyclopropaphenanthrene Derivatives

Article abstract of DOI:10.1002/hlca.19860690412

Base-induced elimination of the sulfonium salt 2i in the presence of furan affords the addition products 7 and 8, derived from 1H-cyclopropaphenathrene (1) and the isomeric cyclopropene 5a (Scheme 3).Upon oxidation, the selenide 2c yields phenanthrene-9-methanol (9), presumably via 1.No evidence for the intermediate 1 is obtained from sulfoxide pyrolysis with 2e, which leads to products formed by radical pathways (Scheme 5).Reductive elimination of the disulfone 3b gives half-reduction to monosulfone 2g and complete reduction to cyclopropane 2 as well as 9-methylphenanthrene (15), but no evidence for the intermediate 1.